Cancelled Contract - I think not... Should be minus 100!

I got a new contract for my son in July of 2023.

Received the device but it was faulty. So I did what I am suppose to do, phone Cell C and advise on this problem. The Consultant was helpful enough to say it is an out of box failure. The log was made and picked up. - That part I was happy with. Forward to 2 weeks later. Still haven't heard a word. Phoned in. Consultant advised me that I should rather Cancel the contract and take out a new one as this device is being returned as OBF in masses. So i took the advise of this person.

August 2023 - I phoned in to hear if the contract was cancelled and if I can now apply for the new device. The consultant told me that the account is deactivated. I understood this and didn't concern me as much.

End of August 2023 - Phoned in again as now I cannot take a new line as I still have an existing line! I spoke to 4 different agents on that day. All ensuring me that this will be done at then end of August.

Roll on November - Just by chance I was on my banking app checking a few things and I see that I have arrear amounts with CELL C!!! Like really guys. I have emailed Cell C customer service 3 times in the last 7 days. No response. Phoned in a spoke to a very nice lady who tried to help me as much as she can but she couldn't access anything as the LINE IS DEACTIVED!

NOW I want to know how can a line that is deactivated still being charged! I want answers, i want this closed. I want this done. YOU ARE AFFECTING MY CREDIT RATING , NOT MY FAULT YOU CAN NOT DO YOU JOB PROPERLY!