"General exclusion"

So here is my complaint. Since last year July, I thought it was ulcers I had. I went to Linmed hospital twice and the bills were almost R200 000 which Discovery paid even if it is not the preferred provider. December I also went to Clinton hospital which is a preferred hospital, they also paid. So now, when a Doctor finally found out whats wrong, Discovery refuses to pay for the Hospital R68 000 and Doctor R8000. I had an operation done Lap Nissen and now Discovery tells me it is not covered because it is a "General exclusion" but last year they paid for procedures in a hospital they don't have on their list. 8 months in and out of hospital which they paid. Now an experienced doctor found the problem and now all of a sudden they refuse to pay. I want to approach the medical councel with this. As they refuse the cover.