How was your buyer refunded?
Refunds on return of items must be made by the buyer opening a return case, and a refund must be made through that case But only after, the item has been returned to you.
If you refunded before it's return, eBay and your buyer deem the item to be unwanted so they can dispose of it as they wish, and here unfortunately , your buyer does not have the item anymore, to send back to you.
@sudz139