MTN and their atrocious service

Took out a contract in 2021 with MTN, ended in November 2023. In November, when I received a call to upgrade, it turns out the contract's already ended and I'm paying month-to-month. How do I cancel this? Go into the store the person from MTN says. Into the store I go on the 1st of November, 16h40. Here to cancel a contract. No sorry, we don't do that in store anymore. You'll have to call 135. But it's too late now, they're closed. Call 135 on 7 November. Fifteen minutes later the contract is cancelled. Here's a reference number and they've sent confirmation to an email address that most likely fails to deliver as I've not used it in 2 years. December comes, money deducted. Disputed. February comes, double deducted. Lodged a complaint. Received a reference number but nothing, absolutely nothing more. (It's now a week. When they pride themselves on attending to complaints, well try to, within 24 hours) And then guess who calls yesterday? Why MTN Upgrades! Says the number is still available for an upgrade. Not cancelled, no no. Three emails later to complaints department at MTN, no feedback. Nada. So I could wait 14 days for them to answer during which time they will have deducted money from me again because the "cancelled" contract is still flourishing. What poor service MTN. How terribly disappointing. And I a refund of the money you took without consent seeing that I the contract was cancelled. That would be nice.