Nebank Overport City POOR SERVICE!!

My father is a senior citizen, when he went into the Nedbank Branch at Overport city to cancel his Will, he was treated so rudely by the consultant who assited him. He requested a proof of cancellation document and was told he does not need one, I would like to ask Nedbank how do we prove his Will was indeed cancelled in the event of his passing and if someone can provide feedback as to why my father was treated so badly for requesting to cancel a service he no longer wished to continue??