Unreasonable penalties

I called Telkom and spoke to at least 2 consultants, Sandra Njoli and Mbali Komane. I explained to them that according to the Consumer Protection Act, Telkom must properly notify me of my obligation to pay whatever amount is due for each month. I then said they failed to notify me of the amount I was supposed to pay by the month end of September and for that reason, it would be unreasonable and/or unfair to penalize me or add interest on the unmet debit order (because I was not properly notified prior). Sandra then said I was supposed to know how much I was supposed to pay each month by now (even though I pay different amounts each month, sometimes R 409, R 611.40 or R 620.70 depending on the usage) and Mbali says if Telkom fails to meet their responsibility to notify me, I must take the blame, if I fail to remind them to meet their responsibility, by requesting the invoice, which is absolute nonsense. If they want me to cancel my subscription, they must just say so. I have always penalties whenever I was notified before hand.