Nedbank bad service

I am trying for more than a month and a half to switch to the new online banking app of Nedbank. The issue is that this business account has a previous signatory phone number as an authentication number on the SMS's. I called their customer services and they directed me to my private banker. So i got hold of the private banker and he said he fixed the issue and removed the number and replaced it with mine. Needless to say its still the same issue i can't switch to the new app. So i logged into the account and had a chat with a lady named Annah on the chat helpdesk and explained the whole story , that was on 18 Nov 2020. She forwarded the request to the banker's manager at East Rand Mall branch so that they can contact me , no luck , no one returns your requests. If you leave a message at he bankers branch they never return your call. So the end of the year comes and the old app will be shut down and we will no longer be able to do banking. To say the least this is pathetic service!!!!