Bariatric Surgery Not Funded as per authorisation

Firstly let me say this is really a last resort as I have made numerous calls to Discovery regarding my complaint and have had no resolve. On the 10th of February 2015 I had bariatric surgery and Discovery was supposed to pay out at 80% however they paid my hospital account at less than 50%, leaving me with a huge self payment gap. They also have not paid 80% of my Specialist Surgeons bill as authorised. This has been noted as an error from the person dealing with my account however after numerous calls they say there is no real timeframe for them to sort it out and I just need to wait (This is unacceptable as I will now have penalties added onto the bill for late payment). I was also promised to get call backs from the agents that dealt with me which never happened. I know need to resort to a complaint on hello peter in the hopes that my hospital account and surgeons bill will be paid out at 80% as per authorisation agreement.