Not keeping to agreed debit date

I've joined clientele because I was impressed with what they had to offer me. after reaching an agreement on my preferred debit date I was satisfied that it would be done accordingly, to my surprise I found out that my account was debited 5 days earlier than agreed witch caused a negative balance on my account. I would like to know if any of the people at clientele are at all educated and if they know the difference between the 22nd and the 27th !!! I even got a confirmation sms confirming the 27th as the debit date !!! I would like a refund for the bank Charges that occurred due to they're lack of incompetence