Harrasment and incorrect billing

MTN does not even deserve this one star. I keep on getting SMS messages and phone calls that I owe them money. Last year when my contract ended, I notified them by email June 2022 as per their instruction that I am not renewing my contract due to financial challenges. I received confirmation of my email with a reference number. Until August 2022 they still took money by debit order. I sent emails since last year about this problem, no one is responding. Last week I got a call from Judy Naidoo and she wanted to find out if my query was sorted. I don't know how long I was on the phone with her, her phone kept on losing signal. Well, needless to say, the problem was not sorted out and she asked me to phone me on a different number. I only have one number. Today I phoned 135, spoke to three different "service champions" and was told to phone back later as they can't transfer me to the correct department! I am so aggravated!!!!!!!!!!!!!!!!!!!!!!!! I think MTN owes me money.