The other day I ordered something on Ebay. It was a "buy it now" transaction. I paid right away. Yesterday, I got an email from the seller apologizing that he didn't have the item I wanted in the right color, and that I could have another color or a refund. I asked for a refund, which he said he'll do by tomorrow.

If I get the refund (which I'm not worried about) how many stars should I give him? Do I still give him 5*, or do I deduct for the mistake?