No help from cell c customer service

I am at my whits end with them. I have a 2 year contract which expired on 9th June 2023. I have been with them for over 6 years 1. I cancelled the contract via phone to customer care on the 9th May. After 3 different calls to confirm exactly when and how to cancel. 2. I was also given an email address to cancel. Which I did on the 9th may. 3.They confirmed receipt by giving me a long reference number. 4. I phoned the branch to be sure a couple of days later and was told my contract had NOT been cancelled. 5. I then went to Menlyn branch. Maxwell there was very helpful and phoned while was there. I spoke with a lady on the phone who was actually quite rude to me. Told me to give them 48 hours. 6. Almost a week later I receive a call and was asked whether I now want to cancel. 7. After trying to explain that I Had cancelled a month ago she repeatedly told me I did not, and am now going to pay the 600 rand. 8.Of course I argued that fact and she put the phone down in my ear. 9. I am a pensioner and an extra 300 rand means a lot me. 10. I feel that my only other option is to reverse the debit order when it happens. Even if I do it every month for the next 20 years.