No cover for my injury

I tore the tendon which attaches to my bicep, I've been in constant pain, I went to go see an Orthopedic Surgeon that falls within my medical aid plan, even the hospital falls under my plan. After paying for scans and the surgeon the Dr then submitted codes to discovery for my operation, all codes were rejected and I was then told by discovery they dont cover tendon tears in hospital, I had to go to a day hospital, unless I fork out R11 000, so my question is why am I paying for a plan which doesnt cover much to mostly nothing, when I took the plan no one mentioned that these procedures were not covered, and when signing into a contract the person selling the contract should disclose what is and not covered in the contract, now I must go to a government hospital but i'm paying R4700 for a hospital plan which does not cover procedures, I am very disgusted with Discovery, this is an organization that's listed with the JSE but operate like a government organization. I contacted them but didnt even get a response from them, my opinion stay far away from them or first go for training before purchasing any of thier products as they dont explain anything to a person.