MTN SA Doesn't want to Cancel my Cellphone Contract

I wrote an email to cancel my cellphone contract on the 15th of December 2025 because it was ending on the 31st of December 2025 and made follow ups on email but I didn't get any response. I then contacted them telephonically and they said it has been canceled. I went to verify that at MTN Store in Maluti Crescent and I was told it will be canceled on the 31st of January 2026 since I have to give them a 30 days notice. On the 11th of February 2026 at 08:24AM, I was contacted by MTN Upgrade using this contact: *** and the lady consultant wanted to offer me an upgrade but I did inform her that I canceled the contract and I will not afford anything else, and she understood. On the 12th of February 2026, I only received a statement for my data contract and I assumed it was canceled successfully. On the 09th of March 2026, I was contacted by an MTN consultant using this number *** at 14:25pm. The lady informed me that my account is in arrears because I didn't call to cancel it, and now it is on a month to month basis as I didn't pay it when I was not even charged on it. I informed her that I did cancel but she loved the sound of her own voice and didn't give me a chance to state my case and I ended up dropping the call on her. I am very upset with the pillar to post service that I am receiving from this service provider.