BigPete
Striker
Genuinely feel for you mate. You confront them, or cause them problems, they'll be back when you aren't there.
The only way of dealing with this is the police. Go and speak to them in person.
Thinking about it, you may need to put cameras up, on yours or neighbors properties facing you. Get an ID on the little bastards and see if you can make a civil court case.
If you give them a proper hiding will move on like