Error by Telkom!

I got billed an amount by Telkom for August 2018. I then paid the amount via EFT. Now they send me an sms saying I am overdue on my account and services will be suspended if an amount more than the statement amount due for August 2018 is not paid immediately. I phoned Telkom asking them what is going on, and the lady can't explain to me why my statement for August 2018 was wrong. It is not my error! Telkom made the error of sending me a statement with the wrong amount that must be paid! Telkom, please fix this issue. I do not believe that my services should be suspended if it was Telkom's error for sending me the wrong amount due!