I would not have left any feedback either as it gives him an opportunity to flame you back. Better off nothing said. Here's an example of my own:
I purchased a topps series 1 world series pin back in May. Card didn't show for a month, so I contacted seller and he refunded. I assumed he never sent the package, or it was mislabeled or something his fault. I did not leave any feedback. I just received the card last week, 5 months after it was sent. The package was fine, label was fine. USPS had just lost this. It was no ones fault but USPS. So, it was a good thing I did not leave negative feedback. I contacted the guy and he even offered to let me keep the card. Instead, I am selling it on his behalf and sending him the money. It pays to be polite and in some cases... not negative.
I purchased a topps series 1 world series pin back in May. Card didn't show for a month, so I contacted seller and he refunded. I assumed he never sent the package, or it was mislabeled or something his fault. I did not leave any feedback. I just received the card last week, 5 months after it was sent. The package was fine, label was fine. USPS had just lost this. It was no ones fault but USPS. So, it was a good thing I did not leave negative feedback. I contacted the guy and he even offered to let me keep the card. Instead, I am selling it on his behalf and sending him the money. It pays to be polite and in some cases... not negative.