What a difficult situation, I can understand your wanting to leave. Even when we're in the right we cant always win, its better to walk away when the stress and suffering outweigh the benefit. Even if popo wanted to take it further it sounds like a he said, she said senario and the people living underneath obviously know the ropes. Natural law will dictate and these people will one day pay the price for their behaviour as long as they remain the way they are. Their lifestyle sounds pretty angry and nasty as it is, they're already in their own private hell.
Reminds me so much of my ex