Physio and phone call

I had rearranged my physio appointment rather than have to attend at 8am next week so I was off to Lowe House Health Centre this afternoon. It has a very shiny floor.
Cardiology finally rang me (late morning) and the lady said that the doctor who was doing my telephone appointment last Sunday had been unavailable. No apology. 
She asked if I'm free this Sunday for a call between 1pm and 4pm but I told her I'm not as I have arranged to meet my daughter for lunch. I told her I cannot rearrange it as it's the only day we can meet up for Christmas (I won't see her again till after New Year as she is going away with my youngest granddaughter). 
She asked could I not take the call while doing this?! I told her no as it's a very public place. She seemed offhand and put out and kept trying to persuade me to agree to take the call that day during those times but I said "I can't cancel the lunch with my daughter." Does she not realise people have organised things for over the Christmas period?
She said she will have to cancel the appointment then (and she said this in an offhand tone making me feel like it was this or nothing). I pointed out that I waited in all day last Sunday! She changed her tone then and said she will have to see if she can rearrange it. I said I hoped they won't forget and she assured me they won't - I am not confident with that. 
She has not phoned back with another appointment yet. If the doctor was not available for his appointments those appointments would have had to be changed and the patients informed but nobody informed me he was unavailable. If there is no back-up to to do this on Sundays then it needs addressing - you can't have people waiting in all day for appointments that never happen.