Why don't you just move? sounds like the best solution all round. They hate you, you hate them; it's not going to get better is it?
Even if the council took your complaints seriously, it's not gonna help with your day to day life there, and instead of waiting/hoping 3 branches of the same family are going to move out (plus four other people) it would be quicker for you to move.
It sounds like the fault is on both sides here. You son has had verbal and written warnings about him