Cell c refuses to cancel the data contract.

Good Day I Walter Mashaba would like to raise my unpleasant experience with Cell C. I had a data contact no *** with Cell C which ended in August 2021, in June 2021 i called to cancel and I was advised that it will be canceled in August 2021, instead of canceling the contract, they increased my premium from R136. 00 to R320.00 without my consent. When i follow up, they told me that I need to pay the the outstanding amount R320.00 of which I did not agree. On the 20th of September 2021, they sent a message that some one will call me, to date I'm still waiting. They are still deducting the premium of R320.00 monthly. Please assist to cancel the contract and reverse all money deducted without my consent.