Vodacom makes it impossible to cancel contract that's done

I've been trying to cancel my contract since 6 Feb 2020, since it's term finished then. Every time I've called them, their consultants tell me that my contract/number is on the old M2 system and that they don't have access to the system. They say that they'll escalate it to the people that do. I've called multiple times and to this day, my contract still hasn't been cancelled.

I have even tried emailing the *** email address, as provided by a consultant. All my emails are bounced by their automated system, even though I have put either my cell number, ID or contract number as requested in subject line.

I can't get help in-store either as they say I must phone cancellation line (which I have been doing), since my number doesn't show up on their systems (due to it being on this M2 system).

This has been the most ********** customer experience I have come across in my life. Vodacom is simply just *****ing my money on a monthly basis at this point. I’ve indicated I want to cancel my contract as it finished on 6 Feb but they simply won’t let me. How do they have a system with people's numbers or contracts on it, that the only consultants you can talk to directly can't access? And how does their automated cancellation email address give you instructions on how to interact with it to get a reply, but then still bounce your email even though you have followed them to the letter?