He claimed unauthorized access of his account. He called the bank or credit card company stating that he did not make those purchases with you. It is a common scam with paypal and unfortunately paypal does not cover your gold sales in its seller protection plan. Your best bet is to claim he is a fraudster and try convince paypal it was actually him pulling off a fraud scam, you will need proof of gold delivery of him on msn stating his paypal email and just upload as much notes/photos to them as you can.