Failure to payout on a life insurance

FNB life has failed our family. My aunt passed away last year on the 23rd of August 2020. I have been trying to call them on behalf of my family (grandmother whose 79 years old and two daughters who are 16 and 22 years) who are the beneficiaries . Both these children depend on our granny for their needs and other essentials that they need since their mother (my aunt) passed away. In 2018 she took a life policy with fnb but when she passed on the bank didn't pay out. The bank stated that the policy payout was declined because she had cancer however my aunt did cancer test in the beginning of August 2020 since the doctors in hospital suspected that she might have cancer, so to be certain she did the test and we were supposed to go back to the hospital on the 3rd of September 2020 for the cancer result. Unfortunately she passed on before we received the results. So we asked the bank for the result that they have which shows that my aunt had cancer since 2016. The bank failed to provide this information to us as a family, they told us that they are not allowed to provide this kind of information to us. We have been sent from pillar to post and everyone shifting reasonibility on whose responsible for the case. As it stands the bank stated that it was going to contact me, It's a month now since and we are still waiting for the results.