Sorry about the crappy situation you're in. Unfortunately people like this take a lot of shutting up. If the police are regularly coming to see them and they are getting complaints from neighbours but still don't shut up then it really does indicate that these people don't give a toss about upsetting other people or getting into trouble. I think if I were in your position (and the noise team intervention doesn't work) I might consider giving my landlord my notice and find somewhere else to live. I know it sounds crap and in some ways it is giving up, but then I think it's just being realistic. I've had bad neighbours in the past and they never did change, no matter how much complaining I or anyone else did.