Change of banking to Nedbank

I have spoken to the call centre digital home loan agent Merc Mazibouko because I wanted to change my account to Nedbank. I was promised that an SMS and the date for collecting my bank card would follow. to date, nothing has been done. Its been two weeks and my work requires a stamped letter from the bank to change my banking details. All I need is that letter and change of banking details done. May I please get help?? I really love Nedbank, but we can't stand on a bad footing like this.