No contact from ABSA when trying to register an estate

We logged a query 3 months ago as ABSA was named executor in my dad’s will. We have since tried to contact them numerous times by email, phone and eventually even went to the bank in person where my mum (a grieving widow of 72) was treated very rudely and told that ABSA will not execute the will because there is nothing in the estate. All I am trying to obtain from them is a letter stating this so I can appoint another executor