Debit date

I opened a 32 day notice and l asked the bank to ensure that the amount of R200 is debited off my cheque account on the 27 of each month this 27 was a holiday either they should have debited on 24 or 28 as both were working days. But they decided to debit on 30 of April and there was no money for that order. Now l have to pay bank charges when it is their fault.