Absa refuses to pay over deceased estate monies

I have requested a statement for the deceased account, Absa refused to provide a statement and advised that I need to obtain a letter of Authority. I have since obtained a letter of Authority and submitted all FICA documents. Absa now refuses to pay the funds over to the Estate and has requested that I prove that the deceased has funds with themselves. They further requested I have an amended letter of Authority. How do I now prove that the deceased has an account with Absa and get an amended letter of authority? Absa doesn't want to pay over the funds. I will go to the media to expose Absa. The CEO doesn't reply to correspondence and neither does the National Head of Deceased Estates. This is the worst service ever. I have previously logged a complaint on Hellopeter and no response.