What about a small claims court action? Its £50 and I think if you start a thread the others may chip in and you can bring it in as a class action on behalf of the others. There’s plenty of evidence here and you will probably find others, also let EBay know what you are doing and give them the small claims number and they have to, by law suspend them trading on their site pending the outcome.
I did it with a garage that sold me a wrong un, I got my claim money back but nothing else but they closed the company.. a little revenge I think.