You listened the tape before you send, it was OK. Then it's not your fault what happened after it left your hands ! Is he someone you had deals with him again ? Or someone just ordered once and comes back with this story ? If it was me, if we speak about a 6-7 euro new tape, and you have more in stock, i would offer to send him another copy only if he pays the shipping cost. And that's only cause i am generous when it has to do with other people's items haha !