Contact the local authorities. Ask them or your manager to set up a task force or neighborhood watch program. Write , write, and write more letters to the manager and to her management company. I am a manager in Texas at a luxury community - - I can tell you sometimes it is easier to just let an unhappy resident out of their lease with no penalties than having to (excuse the blunt statement) deal with their complaints day in and day out. At some point, something will have to give. But seriously contact the local authorities and ask your othre neighbors to do so as well.

I once lived in an apt. that had this problem. The leasing office told me to call the police - but I'd have to file a complaint (and they'd know who signed it). I stuck it out for a few miserable months and moved out as soon as I could.