Unfair

The contract that I sined for with telkom was that my account should be debited on the last day of the month and they were debiting accordingly,and from july I had irregular payments from work they started paying us on the second, third or on th fourth . Subsequently I decided to call Telkom in August on the 3rd if am not mistaken asking the to change the date to the 5th of which the lady explained to me that the money will be debited on 5th of second month (September ) but when they send the statement it was written that amount due must be paid on last day of September instead of 5 th October , then month end September debit order bounced since there was no money and I was charged R 200 for that and the statement came stating that I will be debited on 5th of November and today is the 6th still no debit order, I think I will also be charged that R200 just for the fun of it .....of which is not fair