Sad and frustrated

I would like to lay a complain regarding Discovery. We joined them last year September 2018 as we were in need of a medical. Our monthly payment is R5000 and out of that we can only use R3000 as they call it savings.so last year December 2018 I start only using it at a doctor's consultation and what I know not all of that R3000 was used.I done blood tests at the doctor so that made me wonder when I received an SMS January 2019 this year that one of the tests which cost only R137 was not covered by the medical. How can that be because we pay so much every month and even when we need medication that is prescribed it always comes out that the medical don't cover for it . So now we have decided to cancel because it doesn't meet up with what we call medical and we took the medical for when we dont have to pay over counters or go to a doctor/hospital we'll use it. We call to cancel and they agree to do and they said its cancelled they won't deduct anything but still on agreed month of February 15th 2019 they deducted R6250 that is now said that January the aid is going up. Still even though we ask to cancel they deducted. When we called again to complain the lady said with such rudeness unfortunately we can't get our money back,up from the month we joined and she said we signed a contract with them there is nothing they can do. What contract we ask cause we never received papers to read or to sign all was done over the phone and thats it.no one explained the terms and conditions they comply with.Cause if we did know the experience we going through now we wouldn't complaint about they rude and bad services. We want our money.im seeking advice on how to solve this matter with Discovery. Its sad to take money and hide the truth regarding the service to clients and people. The consultants dont explain to us the terms even if its over the phone why hide that.cause as i said if we knew that this will happened we wouldn't have joined them pls provide us with advice we will gratly appreciate i***** sad and frustrated to be handled with such rude attitude.