Item I Own Listed By Someone Else

Hi, everyone - I have an item (PSA graded Pokemon Card) that a seller still has listed on eBay. I'm the current owner and I'm under the impression that the seller had gotten rid of it, but did not adjust their listing. I've tried reaching out to the seller directly regarding the matter (I provided paperwork from PSA). I reported the listing to eBay 3 times, but have not yet received a response (over 1 month since first report). I'm wanting to sell the card, but I can't do so with another listing still showing the same cert #. I'm not sure what to do... Any advice?