Upgraded my contract without my permission! **** to me as a customer

Late March or early April, I received a call from a Vodacom consultant informing me that I was overcharged for my sim only contract, of which i responded I will be NOT renewing my contract with Vodacom and that whatever she does should not make any changes to this contract. She assured me that it will definitely not. I left it. today when I contacted Vodacom to inform them, I would not be renewing, I was informed that my contract was upgraded! I asked them to reverse that renewal as I was specifically clear on my call that I do not wish to upgrade with them as their service has been terrible the past months! I am super unhappy because that consultant **** to me!