[phobetor00]

So he charged 5% of the order and then you got a refund via amazon? That's pretty good.

Yeah, but now that I know how to SE I'm now wondering how to do it so I can perhaps make a business out of this

You don't need to login into anyone's account to claim a DNA with Amazon. A receipt with order number, address and item description is enough to do a simple email exhange and get your clients refunded. I think they may be asked to change their registred email address on Amazon to another one controled by the refunder, so this communication can happen.