Vodacom Cancellation Nightmare

I've been trying to cancel my Wifi contract with Vodacom since September 2020. I've emailed through a cancellation letter and requested confirmation which was ignored. I've asked a lady in store in Langenhovenpark in Bloemfontein for assistance, she promised that it was cancelled and that they won't deduct any more money. It is now January 2021 and they are still deducting money from my account and it is almost double for the last two deductions. The service from vodacom is pathetic.