I am fascinated as to why so many support the idea of not returning to the OEM. Even if the club was broken when it was sold, the type of damage caused is well within the reasoning to replace based on normal usage (and frankly is becoming all too common nowadays anyways).
What difference does it make whether he gets his money back from the seller, who in turn receives the club and returns it for a replacement only to re-sell? Why burden an honest seller for a mistake that very well could have been the OP's?
As someone who has cracked the face on 3 different Callaway fairway woods in the last few years, I couldn't agree more. Callaway customer service is outstanding and like any great company, they expect to have some warranty replacements.