4 attempts to cancel a contract, with NO luck at all

I had a vodacom contract for a router, which ended in August 2023. In the beginning of August I received a call from a Vodacom employee, regarding this contract. I told him I want to cancel the contract and not continue. on 25 August I saw my bill was still including this router; (which by-the-way never worked) and phoned the cancellation department. Now the consultant suggested that I change the contract to a whatsapp contract for R18 pm. I thought it could be not such a bad idea, and accepted. I never received any confirmation that this ''migration'' was concluded. On 01 September 23 the normal debit order was again included and deducted from my bank account. I phoned Vodacom cancellation department again. Another consultant assisted, and promissed that she will ensure that the contract get cancelled. She said she can see that I did try to cancel the contract. On 01 October the normal debit order was once again deducted from my bank account. I phoned the cancellation department AGAIN and requested assistance with the cancellation. AGAIN I was promissed that it will be done, and a confirmation email will be sent. On 16 October I phoned AGAIN, as I still have not received a confirmation email that this contract is cancelled. This time at least I received a ref nr : ***, and the consultant insisted that the contract is now cancelled. I insisted that she takes up this problem with a manager, as if the contract is still not cancelled; I will write a review on hallopeter. I have still not received a confirmation email. And I checked my Vodacom app today to see if this bill was now amended as promised - and IT HAS STILL NOT BEEN CANCELLED. Vodacom owes me 2 months worth of refund; and the 3rd one is also coming up. I do not wish to enter into any business with this company going forward. This is not service. Where is the ''treating customers fairly'' in this whole ordeal.