I returned an item that didn’t work, I used the eBay return and qr code, I received my £8.88 refund, today I received the item back again, with a Royal Mail sticker saying addressee not present at address, what do I do now, the seller was a terrible pain to deal with during this return and tried to pressure me into only a partial refund and made up the return terms saying if the return was lost or damaged then we’d have more arguments, what do I do now? Thanks.