irritated and bad service

I am dealing with an estate. I submitted the beneficiary's claim form two weeks ago. In between, I phoned the Liberty call centre three times to see what is happening. The Call Centre agents told that they have escalated the case with Death Claims. They also told us to be patient as there is a huge backlog due to Covid.

Yesterday, after not having any joy with the call centre, I requested to speak to a team leader. She promised me that she would get someone from the Death Claims department to contact me. Needless to say no one has contacted us.

In the meantime, Death Claims have sent an email through stating that they cannot verify banking details.

My colleague and I have tried now three times today 3 March 2021 to speak to a death claims consultant. We keep on getting told that the department does not take calls.

How do we resolve this issue if we cannot speak to someone.