Clients are not important to Nedbank

Hi, my son started up his own business about 4 years ago and Nedbank were very quick to help him to register and open up a business account. Since then everytime there is an issue or needs advice or requires a letter or requesting a change in his business name, there has been no response. He has sent emails and phoned and still there is no feedback. How can a bank not respond to things like this. Do they not take his business seriously. He does a lot of travelling and also contracts and he has to send them proof of his account which the name of his business has not been changed. I think this is very shoddy and unprofessional for a bank that claims there clients are important to them.