Oh Sweetie! I know just how you feel, I am a Theatre major and have been in this exact spot before. Sometimes though they do come around and change who they cast and I have actually gotten a lead when I didn't even make a callback. I would go talk to the Director and ask if there is anything you can do. Perhaps you can work on the set or be in the chorus just to stay around the department - it might help you get a role next time ... just a thought?