The seller has likely confused your transaction with that of another. How long ago did you email him? When he sees his mistake, I'm sure that will clear up the problem. At any rate, when you paid you were issued a paypal receipt to your regular email. Simply enter the transaction number into the dispute, as it will prove you paid. The same info should also be available in your paypal account Transactions. Afterward, I would think a sincere apology from the seller might be forthcoming.
