Hi everyone. I am new to this forum. I apologise in advance, this is a very long post!.

We moved into our Housing Association flat (block consists of 4 flats, two downstairs, two upstairs, with fob entry security door) 4 years ago and within months we was getting fed up with the behaviour of the neighbours living underneath us. People would be ringing our intercom at all times of day and night, to get into the block, music blaring, sub-letting, drug dealing - just to name some of the issues. Eventually they were evicted in March 2009 and we breathed a huge sigh of relief. The flat was boarded up for months and we enjoyed the peace and quiet.
The Estate Manager assured us the property was now a "Sensitive Let" - meaning the eventual tenant would be fully vetted by herself before they are allowed to move in. We thought this was great news.... and then the new neighbour arrives! (August 2009).
Within days of his arrival we were regularly smelling his extremely pungent weed. There are nights, even now when its smells that strong its like he's sitting in our front room with us! - its no joke. We reported this to the Estate Manager (as did the neighbours living opposite us) and got told "well that is a Police matter" - charming attitude shown there. Then came the loud, bassy music which he sometimes plays all day and night. Having reported it several times the Estate Manager sent the guy a letter telling him a complaint had been made - this set the fireworks off and he became extremely aggressive and threatening to our neighbours living opposite.
Everything came to a head in November 2009 when the nutty guy downstairs threw paint stripper down the neighbours' opposite front door and shoved a threatening note through the door. He came out of his flat (while I helped my neighbours clean up their door) and made several verbal threats aimed at my neighbours. He then started to come up the stairs towards us, so we had to run indoors, lock the door and call the Police. Police - as usual didn't do much, they warned nutter about his behaviour and told him not to come up the stairs at all and to stay away from us.
The Estate Manager was stunned when she heard about the incident, said his behaviour was completely unacceptable and understood the anxiety my neighbours opposite and us had about staying in our homes (my neighbours opposite stayed with relatives for several days after the incident). She said his action were enough to warrant eviction and asked us if we was prepared to give evidence in court against him. We didn't hear much more from Estate Manager, as she said she needed a bit of time to get the case together and was looking into ways of speeding things up. So when we got a letter in January 2010 saying nutter had attended an interview with the Estate Manager and he had been reminded about the terms of his his tenancy agreement and promised to improve his behaviour in the communal area of the flats and no further action would be taken we was all in total shock! - plus if no further complaints were made the case would be closed in 7 days. We felt so let down and disheartened.
Up to the present day. Now the neighbours living opposite have moved out (they have never felt totally at ease in their own flat since the incident). The idiot downstairs is still here - his pungent weed is still here. My partner and I are quite sure he is dealing drugs. Cars arrive all the time, he jumps in for 5 mins then the car tears off down the road. He keeps propping the security door open, so his friends can get into the block. The music still gets quite loud (my partner spoke to him last week about it and he actually apologised - but to be honest I dont expect this to last). The Estate Manager keeps saying that the cannabis smells need to be reported to the police, because if they can get a conviction it would make a case against him stronger - but unfortunately the Police just aren't interested. We tried to get this point through to the Estate manager, but she wouldn't  have it and insisted anything to do with drugs goes to the Police and noise issues go to her. We feel utterly fed up with this situation - it justs feels like he can get away with anything and no-one is interested in getting this sorted. I really cant see him being moved on any time soon. Looks like it is a case of put up or leave.

Thanks again, it feels good to get it out of my system. Any questions, please ask.