You probably dodged a bullet anyway! Low end, bottom of the food chain prossies, might say they take bookings but really they work on a first come first serve basis.
A similar thing happened to be on Thursday, but the prossie answered her phone and said I was late and she had another customer even though I was actually 5mins early for the confirmed appointment, She said because I didn't arrive within 10mins of the phone call she took another customer

stupid cunt