terrible service from branch

I went to Standard Bank in Montclair and Cornobia to change my cellphone number for updates and for the 5 digits one time pin they send when doing transactions. I have been unable to do ANY transactions from my app. I was advised that I would have to wait 24-48 hours before it changes. It has been more than 10 days and still nothing. It is very frustrating because when you do try to call them they do not pick up. We do understand that it is Covid-19 times but those workingb from home really need to work a little harder because this is completely frustrating.