"Inflexible radiology (scan) appointment booking"

Rang the hospital this morning following a visit to the GP, to make an appointment as advised. Was provided an appointment but I soon found out (only two hours later) that I could not make the appointment.

Rang the hospital back and was told that if I cancelled this appointment I would have to send a form in (provided to me by my Dr) and an appointment would be sent out to me, which could be changed if inconvenient. I asked why this was and I was told that it was because I would have taken someone else's opportunity to book an appointment. I asked if anyone had asked specifically for that date and she repeated the same line above.

All I wanted to do was move it back to another day - I was never told when making the appointment that I would not be allowed to change it once it was made. So now I either cancel the appointment and wait several weeks (or even months!) for the scan, or I try and cancel my commitments on the day that it has been booked for.

I was under the impression that outpatient care was being made flexible so as to ensure that all patients are seen to and appointments are not wasted? If I didn't turn up because I couldn't cancel my commitments, wouldn't there still be a slot available for a patient who wanted to book and called after me?