Refusal to provide proof of bank details

I went to the Brooklyn Court branch this morning (8 August 2015) to get a letter from the bank confirming my Closed Corporation's bank details for a client who wants an original letter from the bank. The business banking section was closed. I then asked the service desk for a letter to confirm the banking details as I have on several occasions asked for a similar letter at other branches and they have always provided me with proof of banking details. This morning the person behind the counter was not sure whether she is allowed to give me such a letter. She then went to two of her colleagues who told her that she cannot give me such a letter and she then told me that she cannot give me a letter. I was too upset to ask for the reason. If the reason from all three Absa employees was that only the business banking section can supply me with the letter, it is not true as other normal service desks form Absa in the past provided me with this. As a customer I find it unacceptable that there was no effort to assist me and that I now have to go to the bank again to get the letter. This is an example of acting in silos at the bank with the customer as the loser.