Its a long story and not bicycle related but everyone is very helpful here so i figured i would ask for advice. I sold a limited slip diff from one of my older bmw's on bimmerfourms and have had nothing but issues with the buyer. I shipped him a mint differential, It was in beautiful shape and noise free. As soon as he installed the part he responded saying it didnt solve his noise problem. I immediately told him that if replacing it didnt solve the problem it is something else causing the noise. Then he wants a refund because he realizes his old diff is fine and he dosent need mine. So he opens a dispute through paypal and they side with him and allow a return. So i am out $100 in shipping now. When i receive the diff i notice that he stripped and realized the mounting points. This a $250 fix in just parts alone. So i call paypal and opened an appeal due to receiving damaged goods. They tell me to take it to a professional for a quote and have them fax in documention of the damage. So after receiving a quote from a local drive train shop paypal reviews the case and decides they do not feel the damages are grounds for a appeal. What can i do at this point? Any one had similar issues?