UNBELIEABLE ANSWER GOT FNB

I have had a personal account with this bank for over 30 years. Every month a deposit is made to cover the debits. This month i forgot to deposit With the result that the debits were reversed . It seems it does not matter if you are a customer in good standing of if you have had an account for a long time. when i queried this I was told that they have no control and if account is overdrawn the debits are automatically revered I would like to find out what their mantra of "HOW CAN WE HELP YOU" applies here what a disgusting way to handle a customer