FNB doing what they want

I actually would even give them a star. In December they took my debit orders off on the 12-15 and i only get paid on the 27 of each month. Then the have the cheek to charge me for unpaid/failed debit orders that is an amount of R110 or so each. I have sent a request for the money to be paid back to me as i did not give them the permission to change the dates. Am i right in asking for them to reverse the failed debit orders.