Debiting my account without my consent!

As off June 2017 The Gym company has been debiting my account with charges other than that of the Gym fee.I had queried them every month since then however nothing has been resolved they are still debiting my account. When i last spoke to them they advised that it was due to a problem in their accounts department and that they would have it resolved immediately however nothing has changed. To date since June they have debited my Account with R700.00 and now when i am trying to contact them i am unable to get hold of them. The service provided by this Gym company is unacceptable. I've emailed them several times to ask them to advise me when this Gym membership is finishing as i would like to get rid of them once and for all but it seems my mails are being ignored and my calls are being avoided. I don't know what to do anymore.The people that ive been talking to is Mandla Sibanyoni and Natasha Larnie