Unfair practice

So tell on forces their clients to have debit orders!! So say you want to pay your bill via eft telkom says it has to be payed 10 days before your debit order that they have for you if it is payed 5 days before the forced debit order and the debit order goes of and there is now money for the debit order then next month you are charged an extra R200 rand to your bill, so how do you pay 10 days before it goes of its not possible when you get played like on the 25 th . E.g you have a bill for November which must be payed in December your debit is for the 5th but you only get payed the 25th so when it comes through then you owe them R200 o not forgetting the bank charges you for the debit that failed so even if you pay on the month that it is due you will be paying late and fell on charges you R200 extra, now you say the debit must be for the 30th but you pay on the 25th on the 30th they debit you again even thou you have payed and again you owe them R200 because it was only 5 days before your debit not 10 days.