Wow, I remember having one of these a couple of years ago.  I let it go and call it theft.

I see it as Its not worth my time or effort for the money involved.

I ban the buyer and put it down to pilferage.

Since larger sellers leave feedback for buyers upon purchase of the item,

Is there a way to change the positive feedback left to negative for these types of buyers?

Or can you reply to the positive feedback left to let other sellers know?