Old mutual refusing to pay retirement for deceased

I am canceling my policies with old mutual,ohk my Sister passed on the 23 April 2024,she had a retirement policy with old Mutual,and she made my other sister a beneficiary in case of her death,its been 6 months now and still no payment made,one of the reason was they are still investigating if deceased was married or has kids,im wondering whats the point of nominating beneficiary if ur wish wont be respected when u die,im never taking any product from old mutual,our beneficiaries are not safe