Buyer Says Coin Was Lost, Tracking Shows It Was Delivered

did you send it priority mail, its insured up to $50? Ive had this happen on both sides, As a seller I didn't have any tracking info so I had to pay up, like $20. As a buyer I actually received the package but the coin was missing from it, there was a small tear in the envelope. The seller thankfully believed me and sent me on refund.

If this personally happened to me Id tell the buyer to wait another week and then if nothing turns up issue a full refund or a partial refund.