eBay can be unfairly dictating users what to do and take robust action without thorough investigation.
I have tried to sell something on e bay after about three years of inactivity. Ebay decided to restrict my account to buy only. When I looked into it they said there was an unresolved issue between a seller and buyer at an address, my ex's address. The dispute was years after we split up , between her and a buyer. I never lived there. I only had an item or two delivered there for convenience. I have raised this matter with eBay explained the circumstances but it was like banging my head against the wall.
They would not listen no matter what.
As for the feedback, you should be able to leave a negative feedback. At the end of the day, it's called feedback? Surely here in Basschat it would be allowed as long as it's constructive, I feel with you.