Buyer Insisted on a Refund and Claimed They would Refuse Delivery

I had a customer order an item and I shipped it to them via USPS. The item got hung up in a USPS facility for about a week and the buyer said it was taking too long. I asked them to wait and I would file a “find my package” case with USPS. They said they couldn’t wait any longer and insisted on a refund. I told them I would refund only if they would refuse delivery if the item was eventually delivered. They agreed to refuse delivery. I issued the refund and a few days later the item was delivered. The buyer didn’t refuse delivery and won’t respond to messages. I couldn’t file a Safe-T-Claim as I had already refunded the buyer. Is there any action I can take with Amazon? Or do I chalk this up to another scumbag buyer thief?