We had this. But their parties went on for days a time. Really exhausting. I phoned the police and they were helpful and did come out to ask them to turn it off. Unfortunately they never did because its not a crime as such. In the end we just gave up and put in for a transfer as our council done nothing either.
Also be careful which way you approach it with your neighbour. I had both neighbours threaten violence towards me and i had my child in my arms both times
(always caught me as we were coming in to the house.) they partied together and joined forces. plus if they have alcohol or more in their systems you dont know how they will react. I hope it gets sorted though as our experience was terrible so know exactly how you feel. On a lighter note our one year old got woken up by it one night and stood up on his bed dancing along