No pay out for Policy after 30 years of paying premium

Policy no *** My parents took out a policy 30 years ago. And 20 years ago my father passed away and I have no trouble to claim for his funeral. They pay out within 14 days. My mother keep on paying R35 pm for her part of the policy. She passed away on the 14th of July 2020. I log a claim on Liberty website and was told that my late father is still her beneficiary and because of that they can not pay out her part of the policy. So much for paying another 20 years to have no benefit. Hope someone can help me. I even had my broker help me with no luck. MJ Nel