Dilemma of Warped LPs - is seller liable?

I have bought a few LPs, mostly on e-bay, which were advertised as Mint or Mint minus and they arrived so severely warped that they couldn't be played, as they hit the suspension of the cartridge. I have not claimed a refund from the sellers, since they were Mint in appearance in one plane:) - question: should the seller refund the purchase amount in these circumstances? I have assumed that the seller did not know and sold the records in good faith. The seller obviously did not play them, I assume, of course. I guess my philosophy is if you buy a used item, you take a chance.