Problems with Housing Association flat upstairs

I would like to ask the advice of your members, please. I own 2 x 2 bed ground flats in a block of four, two flats upstairs, two downstairs. They are freehold flats, close to the town centre and rent well. Both of my flats are rented out to tenants and up until the relatively recently the block was easy to manage.

A couple of years ago the owner of one of the flats above decided to sell and she did offer me and the neighbouring owner the option to purchase but at the time we both declined. Unfortunately the flat was sold to a Housing Association and this is when the problems began.

The Housing Association property is used for short term tenants, women or men who for whatever reason have no place to live and they are housed temporarily until a more permanent home can be found, sometimes with children, sometime children just come and visit. This regular movement in and out of these temporary tenants means that the rest of the tenants in the block are unsettled by continually seeing new people and my tenants below are continually complaining about noise. so much so that they have now given notice siting the continual disruption from upstairs as the reason for leaving.

I have spoken on numerous occasions to the Housing Association and they are really not interested in addressing any of the problems of noise. We have also (the other landlord and I) asked if we could buy the flat but they are not interested in selling either. Other than sell my flat, is there anything anyone can suggest we can do? I have people interested in buying my flat but if the noise could be addressed I’d probably like to keep it.

Thanks in advance.

Mrs P