I sell woodworking plans on eBay. When someone purchases said plans I put them in an envelope and mail them off. I had a customer claim the inadvertently purchased my plans and requested a refund. I have now been charged $15 for his refund and $20 for the chargeback. How can I prove I sent him his plans so I can get my money back? And how do I fix this so I don't have this issue again?
