MTN unreasonable price increase when data contract ran out R395/month to ~R1200/month for 20GB!!!

I've signed up with MTN for a data contract in July 2020 which was on special, R339per month. Ended after 2 years at R395/month as costs creeped up. I did not mind this increase (as the small prints in their contracts always favours them, but this increase was acceptable to me). Since my parents were still using this data contract and in the process of signing up for a new contract I left it to roll over to a month-to-month and knew that this could increase the cost. Despite all the new data specials (which would obviously not apply to my month-to-month) I expected the worst case scenario would be the equivalent cost of prepaid data (R599 for 20GB), which I was prepared to pay for a few months until my parents signed up for a new contract. However, MTN changed my monthly payment from R395 to more than R1160 for 20GB data. I've reversed the debit orders as I would like to take this up with ICASA before accepting that I have to pay an unreasonable amount of money for 20GB data for 3 months. I've cancelled the contract and besides a request for more information and a reference number (Reference number: e4ec8e30-0a58-4461-85b6-5f***9c9) I have not received any confirmation that my contract's been successfully cancelled.