Vodacom contract cancellation problems

I have 2 contracts with Vodacom, data and phone. I just finished my phone one monthend Feb. From late last year they’ve been calling me about upgrade or cancellation to which I was specific that I’m cancelling and not even using the SIM card the phone came with so they should cancel everything, this was months before Feb/March. To my surprise they debited money again monthend March and each time I call, either the consultant hangs up or I’m told I’ll get an sms to confirm cancellation of the sim card which hasn’t happened. I even went to the branch at the Grove in Nelspruit and the consultant just hung up. So they basically want to keep deducting when I keep explaining the same thing. Whether I call or go to the branch it’s pointless. I want my money and for them to stop deducting!!!!!!!!

Please advice