UNKNOWINGLY BILLED FOR 3 YEARS !

I have been going back and forth with Telkom regarding a contract that has ended approximately 3 years ago. I received my last Telkom invoice on 08 March 2020 and haven't received a single invoice since then! Apparently an invoice was issued on 02 August 2023 and I have't received it and my email address haven't changed since I have started using it. Today, 10 August 2023 I called the billing department and apparently I owe Telkom approximately R38 000 ! This is outrageous as I haven't received a single invoice, or statement of account from Telkom stating any outstanding balances. The consultant I spoke to had the audacity to say that she will set up a payment arrangement and I explicitly told her that I REFUSE to pay for something I was not aware of accumulating for the past 3 years. I haven't use my contract sim card for 3 years and it still shows as active on the telkom system. How could this be possible ?! This balance is damaging my credit score and making it impossible for me to open any store accounts. I was told that my contract will automatically switch to prepaid after the contract period ends but this has not happened and I have been unknowingly billed for 3 YEARS !