From a trader, he has refused my money back and become
Aggressive!!
He legally has to take it back or give you a full refund.
I had a similar problem last year with a local car dealer and took him to court. I won, got all my money back, costs covered etc. He also got aggressive with me which the judges don't like to hear
Good luck with it, whatever you decide to do. If you get anyone to look at it or any work done keep all invoices. It would be advised not to do anything to it at all if there is any chance you want to return it.