Ebay is retarded, had a similar issue many moons ago, again you can't leave negative feedback!
However the c*nt left me negative feedback and ebay refused to remove it so I now have a 99% rating. They kept contradicting themselves and ebay said nope we won't remove it you can file to have the comment removed but it will still remain as negative feedback. Otherwise you need to make the buyer change their feeback which wasn't happening.
Ebay can be a pain in the ass, the best they did was refund me the fee's