Paid Monthly Medical Aid Premium for no actual cover

I have been with Discovery for the past 5 years and every time I have to claim. I have had to pay the full amount out of pocket in one instance i had to pay R27,000. . I always double-check my benefits before claiming but they always find a way not to cover whatever it is by stating terms that were never communicated to me as a customer. I even go as far as to call before I claim and make sure I have cover and when they refuse they always say I was given the incorrect information. I honestly don't know why I paid for medical aid and I have decided to cancel and even still I have to pay for two extra months. Honestly an atrocious experience with Discovery every time. The worst medical aid