Neighbours

I live in a one bedroom flat ground floor. After my husband died in 2008 I decided to downsize from a good sized 2 bedroom being I was now on my own. At first I was happy. The neighbour upstairs I had presumed he was on his own. Over the last 5 years it has become at times intolerable due to the noise from his flat. It now looks like a woman living there with him & she has a toddler aged about 3/4 or 2/3. I hardly see him so unsure if indeed he still lives there. The child continuously runs jumps runs jumps banging and banging & to make matters worse the taps when he or she turns them on makes a real loud noise (could be pipes) often keeping me awake (I now wear earplugs during night and at times during day to block out the continuous thumping and banging). Over the years there have been different people living there sometimes for months sometimes it appears for Weeks - all differs - sometimes with children sometimes a number of adults - I am suspicious the tenant illegally rents out his flat making money- all the people appear to be of African/ Nigerian appearance. I have reported to the landlord (Housing Association) after I myself made attempts to knock and speak to whoever is in - the door is never answered but I know there is someone up there. A staff member of Housing Association did pay them a visit some months back & reported back to me saying the tenant was very sorry & did not realise - also he claimed he has members of family visit him - as far as I am concerned he lies - I have seen some of his so called family arrive or leave with large suitcases? Over this weekend again my peace has been destroyed. I knocked on three separate occasions & each time they do not answer the door. As soon as I am back in flat it is quiet for 10mins at most & then noise all starts again - so they know what they doing. I am at my wits end. I have also been under hospital and due to have a cardio angiogram this coming Friday.