Hi just sold an item and waiting for payment. was just reading through the buyers feedback and they have a few comments about not paying

[nikkibart]

the buyer still has a 100% postive feedback score so was just wondering how they still have this and can bid on items if they havent paid on other items. ive already had to relist this item after closing and unpaid item case agains another buyer and am angry that it might happen again shouldnt they be banned or something from buying on ebay? thanks