Document, document, document. Keep track of what happens, when. If police are called, etc. Keep calling your landlord to let them know what's going on. There probably is a right to quiet enjoyment clause in your lease - it's pretty standard language. The noise makers are probably in breach of their lease, the loud noise and fighting also being considered a nuisance, the dog being a danger to others, etc. Those are all grounds for eviction.

Sounds like a lousy situation for you, but people have been evicted from the building I live in for such behavior.