Nedbank Braamfontein staff horrible service

We are a group of six young males who started a stockvel account in 2004. In February 2017 we went to Nedbank Braamfontein branch to open a savings account. A guy called Sam is the one who helped with everything. We have been depositing money into the account every month, not less than 4000. Last week Friday, 27 October 2017 we went to the same branch to put a notice for our money. To our surprise the money that we deposited and the one we being given doesn’t correspond. We called the branch and explained to Sam who told us to call their call centre and he doesn’t have time to look at the figures. We then called a lady called Martha and she suggested that we send her the statement on email , which we did. When we call again and ask to speak her she just answer the phone and not say a word. Even to date no one from Nedbank tried to contact us. I feel like nedbank is operating a crime syndicate and they only give you great service when you open an account and going forward they don’t care. I am deeply disappointed with Nedbank and will never ever recommend people to invest with them because the money disapper . What a useless bank