I received a bad part. What should I do?

thats one reason I like using paypal because atleast you have SOME sort of insurance I guess......if the part is not as described you can file a dispute claim with paypal and they will review both sides of the story and determine who is wrong and get you your money back.

and if the other party involved does not respond to the dispute claim they forfeit the opportunity to voice their side and judgment is automatically ruled in your favor.