To me it depends on what you paid for it. If you paid more than 10 dollars I would ask for a refund. If the seller wanted the card sent back then I would ask that he pay for shipping.
On a side note- I recently paid 2.99/free shipping for a pc auto card /125. There was some kind of black mark and hole in the bubble mailer and the card and top loader got creased in the same spot(I now know to always write PLEASE DO NOT BEND on bubble mailers if sending out cards). I did not even inform the seller of the issue, but I was kind of bummed that I did not get this card for my pc at a great price. What made the whole situation worse was that I purchased a different 2.99 free shipping pc(duplicate) auto card from the same seller 2 days before I noticed he was selling the /125 auto card that I actually needed. I could have saved the seller a couple dollars on shipping/paypal fees and got both of the cards undamaged if I had just looked at this guys other items he had for sale before I paid for the first card!
On a side note- I recently paid 2.99/free shipping for a pc auto card /125. There was some kind of black mark and hole in the bubble mailer and the card and top loader got creased in the same spot(I now know to always write PLEASE DO NOT BEND on bubble mailers if sending out cards). I did not even inform the seller of the issue, but I was kind of bummed that I did not get this card for my pc at a great price. What made the whole situation worse was that I purchased a different 2.99 free shipping pc(duplicate) auto card from the same seller 2 days before I noticed he was selling the /125 auto card that I actually needed. I could have saved the seller a couple dollars on shipping/paypal fees and got both of the cards undamaged if I had just looked at this guys other items he had for sale before I paid for the first card!