Is it merely showing Unpaid in your Purchase History or has an Unpaid Item Case been opened against you? I suspect it is the former, the latter wouldn't really make sense. If it's the first of two possibilities, it is a nuisance and nothing more. You should be able to select it and then make it 'hidden' but you have to be at a desktop computer to do that as you can't access that option in the app on a mobile device.
You might also be able to mark it as 'paid' manually (just to get rid of it on the Unpaid screen) but that might also confuse ebay and cause additional headaches, I can't be sure of that.
Does that help? If not, write back with more details and one of the other members should be able to give you more specific advice.
Sorry to hear that things went south with that transaction but you can be assured that if that seller was asked by ebay to leave, there was good reason for it and you're better off with your payment still in-hand.
