Discovery Health bad service

I am extremely disappointed with the service I have received from Discovery Health. I am a member on the Delta Saver Essential plan. I was recently diagnosed with cancer and under went a operation. My oncologist advise that I required further treatment of Radiation. My oncologist rooms required authorisation from Discovery health before commencing with my treatment. After a back and forth with Discovery oncology department and board of review panel for over 2 weeks, they declined my treatment. I am extremely frustrated and furious that I pay for a medical aid plan that can not help when I need it the most. If my cancer had to spread further due to non treatment who do I hold responsible. I was promised a lot of promises when taking this plan. Discovery say they are the best Medical aid, I disagree. Don't join Discovery medical aid as they can't keep up with their promises. False advertising.