How do I get eBay to close a case in the resolution centre?

a while ago i had sold an item, a bag, which was about twenty years old and listed it as a vintage bag, i started the listing off at ten pounds, not really expecting it to sell, but it did, and in the end sold for £30 (wooo! right?) and so i sent off the bag, but a short time later after the buyer received the bag, wanted a refund, saying that it wasn’t the quality they had expected, I was annoyed because It wasn’t really my fault that the auction ended with the price so high, i really didn’t expect it, nor the demand for a refund, after explaining everything about the bag, quite thoroughly, but now the case has been open for 23 days, and the buyer has not responded, at all. I have no idea what to do! only they can close the case, and i just want my money back after the funds have been placed on hold and i don’t know what to do!