"Operation was cancelled 3 times"

My 83 year old mother was scheduled for an operation on her spine in October 2014. She attended the hospital early on the day of the proposed operation, waited 6 hours with no food or drink, and was then told that the operation was cancelled due to another urgent case. She was offered another surgeon the following day, which she agreed to, was given a sandwich and a drink, and waited a further two hours before having the second surgeon cancel. She returned home and received another operation date in late november, six weeks after her first cancellation. Two days before the scheduled date, she received a phone call to say the operation date had again been put back for another week.

At this point I decided to do some internet research, and discovered via the NHS Choices website that patients whose operations are cancelled at the last minute, and who are not offered a new date that falls within 28 days of the original operation, may select a hospital of their choice at which to receive surgery. I contacted our local Clinical Commissioning Group, and after several phone calls, it was confirmed that my mother could have her operation at local private hospital, paid for by the NHS. At no time was this mentioned to us as an option by any NHS hospital admissions staff, the consultant's Secretary was unaware of this option, and it was pure chance that we found out about it. Why are NHS administrators ignorant about the pledges in their own Constitution?