Obviously we have all had or have neighbours, from hell! which were your most memorable?

I live in a dainty, old building with wooden floors and bad acoustics. It was so peaceful until about six months ago The flats are small, so it is specified that two adults and one child maximum are allowed to live there. I am an owner so the owner upstairs left and rented their apartment out.

Then the neighbours from hell arrived. They assured the owner that their were three of them. A mother and two kids. But in fact I know it’s a mother and father and two kids.

They scream into the passage way, the TV is blaring day and night, they stomp around with shoes on until sometimes 2am and have then woken up at 7.30am to start hammering on a Saturday. If the mother leaves the flat to go to the post box or whatever the child screams hysterically into the passage. The son cries a lot in a whiny high pitched way (he is about 8 I think). Their friends hoot madly at all hours outside. They slam doors, and have extra loud conversations. Of course we have asked them to shut the hell up but it continues. What should we as owners do? Have you had neighbours from hell? Would love to hear about it.