Sorry, but I have a hard time giving money to a company that books an appointment, misses the appointment, and then doesn't bother to call me until I call them. If you have such little value of your customers I can't have respect for your business either.
I know that things come up...but we all have telephones! There is no excuse for this. I don't put up with that from my employees so I am quite sorry that you do from yours.