Can't cancel contact with Vodacom

Hi Vodacom

I've been totally disappointed and frustrated by your service and the way your staff treated me on many occasions. I concluded my contract in December 2020, since then you upgraded my contract without my consent. When I noticed such conduct, I called countless times to have such stupid upgrade concelled but no one helped me. I went to your shop and they couldn't help me as well. I want you to show me when I agreed to such upgrade since you record your calls. I've evidence of one of your staff who was assigned to my case but he chose to leave it such like that. You are taking my money for nothing.