I have filed a claim involving cards with USPS in the past and had success. The main difference was that my package was lost by USPS and never recovered. I had to submit copies of the completed listing, the paypal transaction, and proof of insurance purchased. It took about 3 weeks total and few calls but I was fully reimbursed in the end.
It wouldn't hurt to try and file the claim. That's what the insurance is for. I imagine that USPS would have to keep the item and you would have to provide proof of the damage to the card. Best of luck!