Vodacom contract cancellation

My contract with Vodacom was supposed to end in August 2026. Just a few days ago I received a message saying I should pay R534,99 month end of September. I called their customer service and I was told it’s because there’s an upgrade in progress. I never agreed to any upgrades with Vodacom and yet they are saying it’s in progress, I did not sign anything or agreed to anything. How am I expected to keep paying for a contract that has come to an end ? I’m being sent from pillar to post when I call them, they keep saying they will look into it and they will call me back and they never do. What a terrible service. I need the contract cancelled because it has come to an end there is no need for Vodacom to want to debit from me anymore. There was never an upgrade that I agreed to or signed. They cannot help in store and even telephonically so where exactly am I supposed to turn to? Please fix this.