State Bank Of Travancore — bank staff's behaviour towards the old customer

Hi, my grandmother holds a pension account in the sbt chathanoor branch. She had gone to bank to submit a life certificate for her pension. She is 72 years old and the staff at the bank was so rude at her. They don't even consider her age and asked her to bring all kinds of documents when she submits life certificate every year to the same bank. Even after getting all the certificates they were rude and asked her to come back next week. Wat kind of a behaviour is this?