Bad service from maverick communications

On the 15th of October 2021, I received a call from Carmen Barnes about an MTN upgrade. On the 16th of October, I told her that I did not want a contract and to cancel the upgrade as the consumer protection act allows for this. She assured me that it would be done. I noticed on the 1st of November that my MTN account was still on the new package. Carmen then put me on to her manager. I also made numerous calls to MTN and was told that Maverick had to cancel as I would be charged a cancellation fee. Today, Carmen and her manager refused to take my calls. Due to Covid lockdown and unemployment, I had to rethink this upgrade and conveyed this to Carmen. Please just cancel the upgrade and put me out of my misery. get some expert advice on how to accomplish this please.