We had a similar situation about 10 years ago.
The nice family who lived opposite us in the cul de sac relocated to North Wales, an Asian gentleman bought their house and promptly let it to the local Social Services.
A group of young Somalian adolescent males were moved in, very loosely supervised by a slightly older African lady.
The problems started off gradually, loud sweary rap music, general noise, and then we had drug dealers dropping off 'supplies'.
Rubbish started to pile up outside the house, there was noise during the night and screaming matches from the disreputable young girls who had taken to hanging around the young men.
Most of us in the cul de sac have lived there for years and we all get on very well with each other.
The situation was becoming intolerable, we collectively wrote to the local council, the social services and the police were called regularly because of the drug dealing, all to no avail.
None of us had contact details for the buy to let landlord, but his house was being trashed and these problem neighbours were blighting the cul de sac.
The problem was eventually solved when during a visit to my local I bumped into an old mate, Aitchy (Harbajhan) Singh who used to live round the corner from us.
We were putting the world to rights over a couple of pints and I mentioned what had been happening over the road.
Aitchy said that he'd find out how to contact the buy to let guy, and good as gold he popped round to ours with the address and phone number of the landlord two days later.
I contacted the landlord who had no idea of what had been going on, he received the rent direct from social services and hadn't visited his investment.
They were gone a couple of months later, evicted I think.
It took the landlord ages to repair the interior of his house, and when it was done a really nice local family moved in, and peace has been restored.
Don't put up with anti social behaviour, if this neighbour can afford a Bentley he shouldn't be in a council house.
Get in touch with your local councillor to ask why this obviously wealthy family are in council accommodation.