Vodacom terrible service and ******* cancellation of contract

I have been a customer with Vodacom for well over 10 years and was very satisfied until my nightmare which started this year. The level of incompetence is shocking to say the least. I called in February 2020 to cancel my contract due to the high cost relative to other service providers. I was convinced into a new contract with promises of 10G data and airtime for the next 2 years. I was promised 10G at R129, 500 mins R224, and 65mins voice at R65. Total bill was R392 for 2 years. It seemed like a great deal. In May 2020 I noticed that my data was used up rather early, I justified to high usage. This month June 2020 has been a total nightmare. I am out of data and I know I use way less than 10G per month. I called on 09/06/2020 to enquire about this. I spoke to Refilwe, Sarah, and Justine. They advised me that my package was cancelled in April 2020. No one knows why and no one know why despite the cancellation my bank account is still being debited EVERY month for R392. To say I'm frustrated, angry and drained would be an understatement. The level of incompetence is shocking. How legally binding contracts can be cancelled is boggling to me. This shows the arrogance of large corporates who feel that they can get away with whatever they want to, when they want to. I would like to cancel my contract due to this but I have been told that despite the fact that it is not what I signed up of it is legally binding, another show of arrogance. I am waiting on feedback as I have been advised that I will be called back. I am not hopeful of a good outcome based on the numerous calls that I have made with no remedy to my problem.