Unhappy customer

I experienced a very bad service regarding my cancellation of service

My contract ended in March 2024 and they were forcing me to either upgrade or use the sim only contract as telkom was still providing me with their service of which I wasn't aware of, I put the sim card away after sending an email of cancelling their service

Today as I was upgrading I was told that my account is at risk because I discontinue using their service without cancellation

I told agents who were busy harassing me numerous times telling me to upgrade of which I explained to them why I couldn't upgrade (due to financial strain) the agent was very rude and told me to look for that simcard and continue using it as the service is been provided, I sent them emails in April and June and they didn't escalate or transfer them to the relevant department and now they coming up with different stories and amounts.

Kindly assist in this regard as this will affect my credit score