We agreed on a deal, time and place to meet, and he didn't show up. He did not message to say that he had changed his mind, could not make it, or was going to be late. He also did not respond to any further messages or make any attempt to explain why he did not show up. I waited at the agreed meet up location for nearly 30 mins past the agreed time. I have also waited until the next morning for an explanation before providing negative feedback.