Return to sender

How do you handle a return to sender cancel? The buyer was a guest so I could not message when the tracking changed from delivered to return to sender.

Now 2 days later it shows cancelled and reason return to sender. Posh said atleast I get the item back for my inventory.

What? So my time, packaging, printing, shipping all for the buyer to hand it back to the mailman because why....remorse?

For context.....$10 pair of jeans shorts. Shipped within 3 days.