MTN Worst Customer Service

How does a big organisation like MTN slip up like this.? I cancelled a contract on the 16th of June 2022 and I am still getting billed for it! its been five months now and the amount is now over R5000. Every month I get a reference number, assured and showered with promises of a refund. I even drove to MTN head office today because of this urgent issue. never mind the fact that it took me 40 min to get there! I arrived at 11.50, thinking I had more than enough time to sit with customer care to finally resolve this. As you might guess. I got to the front of the queue think " I'm almost home baby" when.... murphy's law decided to pay a visit. I was left sitting with all the staff looking at me, telling me " we will see you just now see" but sadly no. Two people got pushed in front me and I still haven't been able to see them. I finally had to leave at 13:15 to pick up my daughter from school. I'm sure most people have felt what I felt today.. frustrated, Angry, deliberately ignored and kicked to the curb.. Its just amazing how I have to be the one following up and pushing for answers when MTN owes me Money! MTN don't give a continental about resolving issues but will gladly take your money!. I actually wanted to upgrade my contract too, killing two birds with one stone so to speak. But now having second thoughts about this. I am now under hard financial stress because of MTN, and they continue to charge me for a phone I don't have. I never thought I would say this but MTN has the worst customer service!

I'm hoping someone who reads this could guide me in resolving this issue.

Regards Rory