Poor Service Delivery Nedbank

We have held an organizational account with Nedbank for approximately 20 years. Due to the criteria in place for us to use the same banking institution as our umbrella body we have decided to open a new banking account at another bank. This, therefore, requires us to transfer all funds to the new account. On several occassions we have been to Nedbank CHatsworth to resolve this matter only to be told that the manager is not in and no one else can assist. We are tired of this excuse and wish for the funds to be transferred. Please assist.