I had a guy bid and then not pay, and leave me a negative 'oops'.
When I checked his info, he is registered in the US, but lives in Italy!
For some reason eBay did not consider that invalid, and would not remove the negative. And they never replied to constant requests for an explanation, so of course after a month I just gave up, which is what they wanted in the first place.
I have never had any luck with eBay enforcing it's rules if it involved ANY work on their end, but maybe you will have better luck!
In the almost six years I have been on eBay I have observed their Customer Service has decreased relative to the fees going up; you get less but pay more.
Kinda like Canada Post, but without the local outlet!
Anyway, good luck on that. Don't waste too much time tho...