Nedbank Deceased Estates

My complaint is based on the service (none) that I don't receive from their Nedbank Deceased Estates Department. We are the Executors in a Deceased Estate and the client was at Nedbank. I have sent all the necessary documentation to them to close the account and transfer the funds to the Estate Late Account. These documents were sent on the 11th of December 2020. Up to now I have not received any feedback. I then contacted Nedbank's Complaints Department and they are trying to escalate the problem, but they don't even hear back from them. Please help me to resolve this problem