Well, looks like if someone doens't pay you have to open a case against them, and if they don't reply or whatever, which mine didn't, after a certain length of time you close the case and you get a final value fee credit, and they "mark" it against their account. Here's what the page said once I closed my case.

"You will receive a final value fee credit and the unpaid item will be recorded on the buyer's account."

And it blocks them from leaving any feedback on your account in case they decide to act like an arse. Guess that's about the best ya can do. Although it gives future sellers absolutely zero forewarning, which I think is lame.

Probably not a big deal that they get an 'invisible' mark against their account. I have a feeling if they're behaving like that anyway, they don't care too much if their account gets shut down. They just sign up to a new one.