I am an Ebay seller. I have done this before when I first started, where an envelope required different handling I didn't know about, and had postage due on the other end. I think you could have been a little more forgiving about the small amount due, however if it was held at the post office and required you to make a separate trip to get it I would see why you would be angry. HOWEVER, his response was totally out of line. He should have apologized profusely and offered to send you a free chip (or at LEAST the 13 cents for your trouble!). It's just good customer service on the sellers part. Especially when you are a new seller and looking for repeat customers. I don't think I would leave a negative over it. Some people on Ebay are just plain nasty, but I try not to lower myself to their level.