Bad service from Telkom

I have a data contract with Telkom. On the 16th of September I received a call that I owe them R987, which I am not aware of. I have called their call centre more than 6 times from that date, until yesterday, 30 September 2020, without any joy. Case no is ***4

I am querying the bill and have been requesting an explanation, to no avail. All I get is calls from their collection department, demanding I pay my this amount. On the 28th of September they suspended my account, and I still have not had any call from the biling department explaining the bill.

This morning (01 Oct 2020), I received yet another sms demanding I pay, or they will list me with credit bureaus

Telkom's service is more than **********, and I am not prepared to be threatened to pay until someone calls me explaining the bill. From the feedback I got from their call centre is that, the billing department made a mistake, and surely they cant make their incompetency my problem! Their app is not helpful either, I have been trying to dispute the bill through my Telkom app and it says they are experiencing technical problems. The call centre indicated that there is no way I can either call or email their billing department directly

I receive my invoices via email, and to date I have not received any bill explaining this amount I supposedly owe them.

Kindly help in resolving this matter. Thereafter I am certainly terminating my contract with them