PSA Slab I Own Listed on eBay by Unknown Seller

Hi, everyone - I have an item (PSA slab) that I acquired from an online seller. There is a seller still has the same cert listed on eBay. I'm under the impression that the seller had gotten rid of it, but did not adjust their listing after doing so. I've tried reaching out to the seller directly regarding the matter to no avail. I reported the listing to eBay 3 times (I provided paperwork from PSA since I got it reholder-ed for aesthetic purposes), 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?