Policy dispute, Absa unhelpful..

My mother recently opened an E/L account for my deceased brother, after having obtained a Letter of Authority from The Master of the High Court in Port Elizabeth. My brother who recently passed away was banking with Absa acc name: Sithembele Dlabantu acc number : ***. Linked or deductible from this account are two policies that when she enquired, was told that these policies has one beneficiary each, one Ncube and one Radebe, which are unknown to us as a family and we suspect are *****ulant. Absa refuses to help my mother who has been given rightful permission by The Master of The High Court to my brother's estate based on the existence of two nominated beneficiaries which we suspect are *****ulant. I would have expected Absa, in their quest to help my Mother to produce a document, original, where my brother had signed nominating these beneficiaries, to be availed, that was not done. My number is : ***.