I'd give them another call on Monday, today being Friday most place are pretty frenzied. Monash were a bit like that too.
Laser does hurt, but it worked really well for me. I just treated it like a mild sunburn and put a cold face washer on it until the heat had gone. That worked well.
It might help while you are off to write up a short autobiography detailing when you first had uncertainty about gender etc, to save time organising your thought for the first session. They are usually an intro regardless of the issues involved.
Hope things go well.
Karen.