Mtn unfair business practice

I had a 36 months data contract with mtn which gave me 300GB day and night data for R321 per month. Towards the end of the contract, I received an sms that my subscription would change to R1842. I requested a call so I would cancel the contract. No call came through. A day before the contract expired I received an sms that an order had been submitted. Data was credited to my account and at the end of that month I got billed about R2200. I called them so that I could request a cancellation. After a lengthy call being transferred from one person to another, I eventually talked the person responsible for contract cancelation. Initially I received an sms that the contract would be canceled on 16 April 2025, a date which was later changed to 11 May 2025. To my horror, today, the 11 the of May I received another sms that an order has been submitted and I will be billed R2119. Mtn is forcing me into a data contract taking away a huge chunk of my salary against my will and consent. When the terms of the contract were changed, I was never called or consulted. Imagine being moved from a R321 contract to more than R2000 without consultation.