I would have called to do SDC...always easier than at the airport, especially if you've already checked to see what is available. And I would also send a complaint with the details. There is no excuse for that kind of treatment, regardless of any status. Frankly if the verbal exchange was exactly as you said I would have asked for a supervisor right then and there. I don't expect the world but I do expect people to do their job and treat me with respect. The exchange, as posted by the OP, is not that.