Those are scammers. Don’t even respond to them. I know many who have been screwed over by ebay’s buyer protection policy. Example: chotski sold on ebay returned for having a chip. Seller knows the returned piece has been substituted, but eBay doesn’t care. Several sellers of vintage guitars have reported instruments returned with swapped parts. No eBay. Craigslist only. Sell for cash, in person, IN A PUBLIC PLACE.
My boy sold an item which was described by the buyer as "not as described". My boy said "Send it back for a refund." He got the package back and it was a brick shipped in a priority box. eBay, in effect, said "Tough Noogies, pay any way".
I've been selling on eBay since the '90s and have not had these kinds of experiences, but then I sell antique reloading tools and dies and work with an ethical crowd.