Here's what needs to happen. . . . Kevin, you have a questionable past you can NOT deny. This amp could have been blown before hand, and it could have been blown by the user. It doesn't matter. What you need to do is to eat it. Give the guy his money back and take the amp back. Don't use UPS for a claim. If you need to do that, refund his money first, then get the amp back and deal with UPS on your own accord. Don't make him wait on them. It sucks for you, but this is what you need to do to prove you're an ethical business man.