Complete lack of service for deceased estates

I am an executor for several estates where the deceased persons had accounts with Nedbank. I visited Fourways branch on 26 October and again two weeks later and handed in all the necessary documents for 5 estates. I have followed up on email but get no response. For he one estate we have handed in documents four times over the last year. Why is is so difficult to close these accounts? The other big banks all have deceased estates departments that you can email direct but Nedbank expect you to go into the branch and then ignore you.