Ridiculous delays in closing accounts for deceased estates

I am an executor of estates. I have two estates where we submitted all the required documents for pay out and closure of bank accounts on 7 February and 31 March, but to date, we have not been paid.

I can't understand why Nedbank takes so long to finalise these cases (all while earning fees) - one of their competitors does this within a week.

Their estate department does not have a direct contact number, so it is not possible to contact them telephonically.