medical aid premium increase

Last year i joined medical aid for my father since he is unemployed and discovery had given me a reasonable premium on keycare plan, everything was fine no complains the came 2016 january premium went down i was excited it became 290 i called and asked they said it was the new premium atleast i can save R40 little did i know that they were fooling me in February they decided to debit R830 which i didnt have so it left my cheque account on a negative balance when i called and asked they told me fees have increased wow without my knowledge? I wasnt going to afford it so i told them to reverse the money and cancel the membership they told me to reverse it at the bank and they have cancelled the membership but again came march they still debit leaving me at a negative and me having to pay bank charges while the membership is cancelled i am tired of their service the attitude i get when querying this its annoying.