Refuse too pay out policy

My grandmother passed away in April last year we went too claim policy money from Dove they informed us since my granny didnt have a benificiary on her policy we have too apply for letter of authourity from High court which i did in the same month of April last year i only recieved it in January this year i then took it too the office of Doves with all other documents when i was informed that i cant claim the policy money anymore since 6 months already has passed since my grandmother death in which i should have claimed the money for me its unfair since they requested the letter from High court what was i supposed too do the policy were paid up too date