Contract Cancelation

I contacted Cell C in April to cancel my Contract which was a monthly Subscription of R359.93. When i called them the first time I was told I needed to pay +- R200 to cancel as my subscription would end in June. In April when I called the second time the Agent told me i needed to pay R500.59. upon disputing it he explained that it included the rest of the month as I needed to give 30 days notice. I agreed with him and then made the payment. I called back to confirm if payment was made and they confirmed and canceled my contract as per the agent and I received an email stating that proof of payment has been received and allocated with payment reference used. On 28 may R217.45 got deducted from my account which I did not take note of at the time. On 28 June R359.03 got deducted which I did not take note of as well. On 28 July R705.13 got deducted and I called in to ask what the amount being deducted was for and the agent said that it was for the contract that has reached the end of its special and the original amount was R705.13. I then explained that I canceled my contract in April, and the agent responded that my account was still active. I requested for it to be canceled and a refund to be issued, they said they could not issue a refund as the account was not canceled. i asked them to escalate it to the Cancellations department which they did and was told that they will call me back in 5 working days which would have been 04.08.2021. on 06.08.2021 I received a call stating that they have finally canceled my contract and I asked about my refund they said they couldn't refund me. on 28 Aug 705.13, another amount got deducted and now I have had enough. they keep calling me for upgrades which I am not interested in as I have a subscription with another Service provider.