Disappointed in Discovery Health

I have a damaged neck and have undergone three surgeries. Discovery are are fully aware of my pre-existing condition. My neck has been particularly painful for the past six months and in December 2014 I consulted Dr Mike du Trevou who referred me to Dr S T Govender, both of whom are neurosurgeons. Dr Govender suggested that I undergo a Rhizotomy that involves a day in hospital as it is performed in the theatre under general anaesthetic. Dr Govender told me that Discovery have a protocol that before having the Rhizotomy, one must undergo a facet block which cost would mostly be from my own pocket, not my MSA! The third person at Discovery suggested that I send a letter of motivation from the Dr which might allow me to have the procedure. I did that but Discovery have declined both procedures with a explanation about protocols. I was also warned that should I go ahead with the Rhizotomy, I would be responsible for the whole cost as they wouldn't even pay for the hospital. Dr Govender admitted me to hospital for pain control for two days and Discovery covered it which I find quite ironic. I really need to have this procedure as I'm constant pain and have referred this to the Ombudsman