I have just tried the 722111 number above and tried to make an appointment.
I was immediately told that this was not possible on this number and that I needed to redial the 08444 number.
When I protested that this would be more expensive for me to use, I was offered an apology but told that this was just the way of the world. They categorically stated it was not possible to use a Geographic number to make an appointment.
The person I spoke to was of the impression that 08444 was a National Rate number - despite the posters littering the surgery advising that 084xx is a local number which they are using instead of the old national number!
I think this is worth taking further with the practice manager...