That is ludicrous! It's her screw up and she should be apologizing. She must have a pretty damn weird scheduling software to let you schedule in the past. Maybe she has found a way around the spacetime continuum! I'm sorry to hear that. The invoice for a missed appointment is a slap in the face...
I really don't know MD well, can I look around!
!BBH
RE: The Doctor Who stood me up sent ME an Invoice for Her No Show