I completely understand your problem. I'd say I've experienced worse in the form of parents being utterly uncaring of the people around them. I still haven't seen the second half of Mamma Mia because of a mid-day screening I tried to go to with at a theater with only myself and a group of two women and four or five kids, two of which were playing with strobing light up toys in the aisles during the film. The only solution I had then was to leave and get my money refunded.
You're right. Most theaters (unless they're scanning the audience on occasion for video recording devices) don't have staff checking in on the film and audience during the screening. So, what is a person who wants to enjoy a film in peace to do? First, there is (in most of the major chains I attend) a real movement towards respectful movie-watching. Many theaters have pre-show notices or videos telling the audience not to talk, or text and to turn off their phones during the screening. Hopefully, if this continues, these parents will realize that curbing their child's (loud) excited exclamations is appreciated by the audience.
There are a couple of solutions. I'm listing even ones you have set aside here for completeness... I like to put them in two categories because I find that, often, the solution is to avoid or try to minimize the chance of there being a problem at all rather than solving a problem that is already there.
- You can (potentially) disrupt the film further for the rest of the audience by attempting to get the parents to quiet down their kids.
- You can leave temporarily (risk missing part of the film) and ask management to address it, which has the same issue of disrupting the film, possibly worse than if you did it yourself.
- You can leave the theater and ask for a refund, opting to see the movie another day/time. This has the risk of recurrence, though the "proactive" section below can limit that.
- If the theater's not too crowded you can move to a different seat. Depending on how loud the child is and how sensitive to this you are, YMMV.
- Tough it out and ask for a refund afterwards. Ask the theater to check in more often for disruptive audiences.
These are things that you can do to limit the chance of this happening. They aren't 100% and they require that you limit when/where you see films but if seeing the film with a chatty kid will ruin it for you, one of these may be your best solutions.
Find a theater that has fewer children attending. We have two theaters near us. One of them attracts lots of large families, the other doesn't. We stopped attending the theater with all the kids because of the example in my first paragraph. My movie-going experience has improved since then.
See a screening at a time kids are less likely to be in the audience. After 8 on a Friday or Saturday or after 6 on a weekday. Yes, you have to pay more because these aren't matinee prices but many chains near me don't really do matinee pricing much any more, sometime only the first screening of the day.
Find a theater chain that has staff in the theater at all times (or most of the time). Here in Austin we have the Alamo Drafthouse, which has table service in the theaters. They're not everywhere quite yet but they are awesome and expanding all over. Dinner and a show all in one go and the ticket price isn't marked up because they make tons of money on food. There are other similar chains that are around, too, like iPic.
I hope that, eventually, everyone will follow proper cinema etiquette and keep quiet in a theater but, until then, I hope that you can find some relief using these suggestions.