Is the PayPal time limite 45 days? if so I guess they filed via eBay because it was too late for PayPal (could always do a credit card chargeback if they used one and are aware that they can).
If you sent via Small Packet and the value is under $100 tell the buyer you will file a claim with CP and send him a refund when the claim is settled.

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915
- answering Trolls is voluntary, my policy is not to participate.