Appalling estate management service

I have been assisting in wrapping up an estate for almost a year. The lack of communication and urgency from Standard Bank Trust is frustrating. The first administrator moved and handed the account over to a second who has only communicated once in two months and doesn't respond to my emails. The only helpful person was from their call centre who forwarded my request to a third administrator. When I followed up with them they forwarded it to a fourth person. Their email signatures only give land line numbers which are never answered and forwarded to a call centre which has a high call rate and no-one answers. I called to speak to a manager who was not available but I was given an email address. I sent an email to the manager and have also not had a reply.