Vodacom medical aid contribution

I am highly angry and frustrated. For the pass 3 months "Vodacom medical aid contribution" has been debiting from my bank account.. I don't know what this is nor did I speak to anyone about a medical aid so how the hell did they get my banking details? I called Vodacom but no one can assist me as they are ***********. The services is pathetic. Since May - July 3 amounts went off from my bank account.. I don't have a medical aid card or medical aid in general.. Who gives you the right to debit from my account for something I don't have. I need someone to contact me on *** as I want this matter to be sorted out ASAP!!