Through trying to be decent, and do the right thing, you've allowed this to drag on for way too long mate . You see, people like the charmers you've described here, don't see you as being a good, considerate neighbour..they see you as a mug .
However, there are two methods that you can employ to get some peace in your own home ;
Firstly, there's the legal route which involves the police, the local council, and the Environmental Health services . If used properly this method will work, but will probably take some time .
The second method isn't a legal route( so I won't go into details here ), but it's guaranteed to work pretty quickly .
PM me if you're interested in futher info on these solutions .