Discovery Medical Scheme Disappointment

We have been with discovery for years now initially on a hospital plan and as of two years ago we upgraded to a full medical aid. I went to a third rheumatologist yesterday with the hope of finally finding some relief to my ailments. Fortunately the doctor I saw yesterday examined me really well and knew exactly what he was talking about. Going forward he wanted to admit me on Monday in order to run tests on me in order to confirm his diagnosis. I got a call from him a short while ago saying that my medical aid did not authorise my hospital stay. The question is why am I paying such an exorbitant amount every month if I am unable to make use of it????? To me the only people who are benefiting from this whole thing is the medical aid. Since when does the medical aid decide what we can go into hospital for? In that case shouldn't the medical aid pay half towards the premium? If my premiums are being paid by myself why should the medical aid determine my treatment??? This sure as hell is daylight ******* in my eyes. This stupid system needs to be reviewed. We are paying for a service and we have a right to make use of it. Not discovery benefitting only. I am utterly disgusted and disappointed . I wonder if other medical schemes operate in the same manner.