Unable to reverse a debit order

I have been trying to reverse a debit order now for quite some time. I contacted the customer service department and after holding for 20 minutes advised me that the reversal could not be done telephonically. I would have to visit a branch which I then did. At the branch I waited 2 hours before being assisted only to be told that they too could not assist. My question is if I own an account with you why are you not able to get my money back? This is extremely frustrating and I would like an answer on this. It is time consuming and also a loss of airtime as you need to hold for very long