How should I follow up if a polite request to adhere to the rules is ignored or declined?
An Example
Dutch trains have special silent compartments (Dutch: stiltecoupé), where people are supposed to keep quiet — no conversations, no music, no conversations on the phone.
Sometimes, while sitting in such a compartment, people who don't know or don't care, start talking. I can approach them and politely ask them to be quiet, please, since they're in the silent compartment.
While most people will comply, some won't and will either ignore me or give a rude reply.
The Question
How do I follow up? It's not just in the situation described above, it could be neighbourhood kids trying to cut large branches (they brought a saw) off the tree in front of my house (not my tree but a municipal tree), for instance.
What do I do when a polite request to adhere to the rules has been ignored or declined?
My preferred outcome would be for the people to cease their unwanted behaviour, but at a minimum I'd like to save face.
("Please stop that." "No." "Oh, okay.")
I'd like to note I'm not a stickler for rules — at least, I don't think I am — but I would like people to follow them if they align with my personal preferences — a quiet train journey; not having a barren stump in front of my house.