Nothing. It seems the buyer has decided not to return the item and is selling it on themselves instead, possibly to save on return costs if this was a change-of mind or does-not-fit return.
If the return request is still open, you could ask the buyer to close it if they no longer wish to return. But if they don't, and they don't return the item, the request will auto-close in your favour after 30 days.
@fasey1
