Telkom Not a good business

I received my final invoice on the 1st of October that I'm owing Telkom R12.00, surprisingly my account has been handed over to Nudebt that I owe R343.00 which is not on the statement. On the 25th of October Telkom debited R355.00 from my account and Nudebt is still sending me messages that I owe them R1143.00, when I try to call Telkom and I can't find them on the line for voice call. This is so unprofessional for Telkom, how do you handing over someone to debt collectors without even speaking to them? There was no communication between me and Telkom regarding the outstanding amount. I was handed over on the 12th October 2024. This company seems like is ****ming it's customers.