You can moan 'til you're blue in the face at a council, they won't do a damn thing! Your best bet is just to record everything that goes on either on paper or on video cam, compile a good amount of data and send it to them!
They'll send the disruptive family a letter which is then followed by a visit and the council members will set the family certain targets which they must adhere to. I've no idea what happens after this, probably not alot
We've had similar problems with our neighbours! We live out in the country and they're the only family in 5-6 miles that cause any problems. Music from early morning to late night through the wall "thud, thud, thud", screaming and shouting, fighting, drugs. We've just spoken to the council and they've definitely had the letter from them as 3-4 cars that are rusting in their front garden have started to move about. Recently found one of them parked near the Zed!! Think this is due to the fact that a council house tenant may only have one taxed car on their property i believe!
I understand your troubles!!