Worst service in SA from MTN

I took out a MTN Home Wifi contract on the MTN website - it was confirmed that there will be Wifi at my residential address. The router was delivered and 24 hours later it was confirmed that there are no Wifi access for MTN at my address. At this stage, I had to pay the November and December 2024 installments as this had to be paid before the router could be delivered. I phoned the call centre, and they confirmed the cancellation is noted on record, I must just take the router to my nearest MTN shop, which was Centurion Mall. That was done and confirmed received on 13 November 2024 at 18:15. On 4 December, MTN tried to debit my account. Firstly, the account was paid for December already on 9 November 2024, secondly, the cancellation was already on record so why debit my account? I reversed the debit order. On 4 January 2025, MTN again tried to debit my account. I stopped the deduction and it was reversed. Then I got a notification that I will be blacklisted yet MTN cannot count. If I pay for November and December in November, then WHY debit again in December. Cancellation is finalised but yesterday I received an e-mail confirming the premium for December is still outstanding?????? It is a waste of time to phone the call centre as they cannot help or the robot just says Invalid option. E-mail also doesnt work, as Customer Care does not work with Billing?????????? This is pathetic. I need confirmation in writing that there are no more outstanding amounts and that I will not be blacklisted - actually you owe me the December premium. Can somebody who understands contact me as I cannot struggle on the phone with the call centre. The whatsapp line to which I was referred are only to buy airtime, so what is the point????