Little interest from Nedbank small business customer care

I am a small business owner and now trying nearly 2 weeks to get into my business account, I know the old banking app was replaced by a new one but ever since trying to get the new app from Nedbank small business is basically a no show or help. I have phoned numerous times to speak to my banker but he is never available and does not return left messages or calls, so I cannot get into my bank to follow up on payments. I definitely must change to another bank who is able and competent to help their clients.