- When they are chatting with my co-workers and I need to ask the next detail to enter. Currently I wait for a pause in the conversation or try to catch the customers attention but this is not very successful.
I'm assuming that either the customer or your coworker has line of sight to you.
If the customer does, make a gesture (raise your hand, look like you're in a hurry to ask a quick question). It works better if it looks spontaneous (immediately doing so when looking up, rather than standing and waiting for a while).
If your coworker has line of sight to you, then they should redirect the customer. When the coworker is speaking, they can stop speaking, and look at you, which will redirect the customer's attention. If the customer is speaking, let them finish. Your coworker should intentionally leave a gap of silence so that you can ask your question.
- When I have to ask for the customer's bank details. Whether I ask for their card, or for them to read it aloud, it feels like I am crossing some line.
I would suggest mentioning that the bank details are needed, rather than ask them for it. It's a minute difference, but stating that the details are needed absolves your role, it negates the inference of crossing a line (on a personal level).
Subsequently, I would offer them to enter it themselves (in private). If you prefer this option to doing it yourself, you could e.g. ask if it's okay if you get a drink while they do so, and ask if they want something.
If you're okay with entering their details, and they seem hesitant about doing it themselves, I'd simply change stance and offer the opposite.
The next step of the form requires your bank details. Would you like to enter those yourself?
[If customer quickly agrees] I'll give you some privacy. [If it's customary:] Can I get you anything to drink?
[If customer is hesitant] Or, if you want, I can enter them for you.
A lot of situations like this can be handled by quickly reading the customer's response, and if you notice hesitance, offering the best option that is opposite to your initial suggestion.
If you can quickly spot their hesitance and offer them a viable alternative before they even had to say anything, then they will generally feel relieved that they didn't need to "deny" your initial suggestion. That creates goodwill between them and you, which makes the rest of the conversation safer, in terms of the customer getting offended by something you say.
You mention that your question is limited to people who are generally not tech-savvy enough to enter the details themselves. But I would suggest that you suggest them filling in the details themselves anyway.
The goal is not to get them to do it, but rather to have them agree that they rather have you do it. If they agree to that, they can't get offended that you're asking their details.
- When I have to ask for a persons Age, Weight and Height. I know some people can find these questions personal and they are not easily understood to be connected to the device, although to sign up they must be entered.
If there's no intuitive reason for asking these details, lead with mentioning that.
If the explanation is simple, follow up with a short explanation.
This may be a seem unexpected, but I need to enter your age, weight and height. This is because [simple reason].
If the explanation is not simple, explicitly say that you're cutting a long story short, and explain how entering the wrong details could negatively affect them. I'm inventing an explanation for the sake of example.
This may be a seem unexpected, but I need to enter your age, weight and height. To cut a long story short, these details help with tailoring the device to you. Otherwise it might feel uncomfortable when you wear it around your chest.
If you had skipped over the explanation, the customer could've inferred that you think they wouldn't understand it. But by cutting a long story short, you imply that you're saving them some time, rather than not wasting your effort in explaining it to them.
For the same reason, it's good that you explain the negative consequences of entering the wrong information. This implies that you're trying to prevent problems, which is a good thing. As opposed to being nosy :)
Note that neither option explicitly asks for the details, it only explains why it's necessary. The customer will either agree with you (and provide the details), or he will disagree with you (and in such a case, you avoided having directly asked something that offends them).
It also helps to clarify (non-verbally) that you're following the script. If you look like you're following the form field by field (or, on the telephone, you sound like you're reading a premade sentence), then the other person is likely to infer that you're not personally offending them, and that you're only asking because it's necessary for the form.
- When I mishear them and have to ask for them to repeat (especially the personal details) over and over.
I struggle with this daily. My hearing isn't bad, but I do have issues parsing the sounds I hear. I often have to ask people to repeat themselves.
There isn't really a one-size-fits-all solution here. Some customers are liable to get annoyed quickly, others will be understanding. Having worked on a call centre helpdesk, I can give you a few tips to make it the least awkward:
1. Repeat everything you understood, to show that you were listening.
Customer Does the device have a poeizpfnpfzneu?
You I'm sorry, I didn't quite catch that. What feature do you want on the device?
There's a double whammy here. Firstly, it telegraphs that you are making an effort in understanding them, and that you were paying attention.
Secondly, because you already repeated part of their words back to them, they are likely to respond with only the word that you didn't understand, instead of repeating their entire sentence again. This makes it easier for you to understand that one word.
2. Put the blame on yourself, but only the second time it happens.
The first time it happens, simply ask for clarification. Anything can happen once.
The second time, apologize for having to ask again. If there's a mitigating circumstance (loud environment, speaking a second language, auditory problems, ...), mention them.
If it happens again, revert to asking for clarification. No one likes to hear the same excuse over and over, it starts coming across as disingenuous.
3. If you can get away with it, ask them to spell it.
Generally, you're more likely to get away with it if it has multiple syllables (which you can generally make out even when you didn't catch the word).
It's not impossible that you end up asking to spell the most trivial of names, but that's a risk you take by playing it this way.
4. (Sneaky) Ambiguous questions can elicit extra information.
This is a relatively well known trick, e.g. if you forget someone's first name.
You I'm sorry, what was your name?
Customer [slightly offended] ... Paul.
You Sorry, I mean your last name.
Customer [no longer offended] Oh. Whitby.
It's sneaky, but it works. They give you the name, and simultaneously get mildly offended that you asked them that. So in response, you redirect the question to a disambiguated version, and pretend like you already knew the first answer.
Not everyone can pull this off, but it's relatively easy to do if you can play it cool and not stammer your way through it.