Poor service from MTN

I am a client of Supersonic who is a subsidiary of MTN. i terminated their services in September 2024 due to poor service. My wi-fi went off and I received no assistance even after I called in. The agent on the other side was unable to resolve the issue and promised to call back which never happened. Another person unrelated to Supersonic assisted me in getting connected and I cancelled the services of Supersonic. I am currently in my notice month and the debit order for October went off. On 10 October 2024 my wi-fi again got disconnected. I asked my new service provider to find out what was going on and he informed me that when he contacted Supersonic directly they informed him that I am no longer a client. He called Metrofibre to take over the line. Metrofibre came back to him after verifying with Supersonic and informed him that according to Supersonic I am in my notice period and they can only relinquish the line 1 November 2024. In the meantime I am without wi-fi for which I have paid and I can not appoint a new service provider.