Angry client

I'm so ****ed with Vodacom, they just playing game with other people's money, I think maybe they believe that we are wealthy. I finished paying them in December 2020, when I called them to check if the money is reflecting on their side or not they then tried to sell me one of their products I refused at first but ended up taking it. I saw that I don't need that airtime they offered to me because I'm no using Vodacom on a daily basis, so I called them a week before 31st of December 2020 to cancel that contract and I was told that they can cancel it but because he is not the one who sold that product to me so he will tell the guy to call me the following day as he was not in that day. The contract was supposed to be active as of the 1st of January,now when I call them yesterday I was told that the account is handed over, how can they hand it over without my consent? In April one of their agent called me about that contract as it's in arreas I explained to her why it's in arreas and she said she will get back to me to my surprise the account is now handed over without my consent without resolving this problem. That time I don't even know where that sim card is.