Contract cancellation

Hi hello Peter Vodacom’s service is nonsense, last year they called me and offered me to upgrade from the 2G contract that I had at the time to a 5G, I accepted the offer. But to my surprise at the end of the month they deducted double the amount. When I called them to query about why they are deducting double, I then asked to cancel the contract, they sent someone to collect the new router on the 15th October 2018. But they have been deducting money from October last year till this day. They failed to cancel my contract, yet they are able to deduct money from my account every month. I have been calling and emailing them, yet all my efforts to get my money back are in vain. Yet I’m losing money, paying for something that I don’t have. The only response I get is that my case is “with after sale” and promised that it would be sorted in 7 days. 7 months later, I’m still paying for it. The annoying thing is that they were very quick to collect that router.