Hello 'neo',
In and of itself the presence of a negative does not constitute 'abuse'. So what exactly do
you mean when you say the "buyer abused the feedback system"?
Granted, it's not a very useful comment, and coming from a red-star user, that person knew
what he was doing. People are allowed to state their "opinion" in feedback, but not to tell
the truth about what happened.
Stupid or what. 
So where and how did you make this report? Did you go to the top right corner of the page
here under Customer Support and choose Customer Support to get a phone number and try to
get the negative removed by calling ebay several times until you finally find an attendant who
will remove it?
That's what sellers usually do. 
But if you do nothing and wait and hope, you wait and hope
in vain.
If you do decide to call and have it removed, make sure you have a well-reasoned defence
line up in advance.
