Originally Posted by mahasamatman

You're right that we haven't heard the whole story, and I see no indication that the statement was at all "hurtful", though the language barrier may have made it seem so. Just as likely is that the "you don't deserve to be in C" comment was really a comment by the agent that she didn't see a valid upgrade. This happens all the time when people have boarding passes they shouldn't have for some reason.