sanlam trustees pay money out that's NOT on policy

Hi there I'm just wanted to find out, if someone passed away and there are selected people's on the policy. How can sanlam trustees give that money to someone else. My mother passed away 2013, and we 3 people on that policy. Now sanlam trustees want to give that to half sister, not on the policy. Now her dad Jan **** to sanlam and said my mom did pay monthly fees to her,and she stayed with my mom. That's bull. Her dad takes her away on aged of 1 year. He put the welfare lady on us. I stayed with mom,I was there when that lady and him was there. He called my mom \lessen, *****\"and said we will never see her again. We try to visit her on her birthday, but the dad said bad things, she felt like a dog every year. I tried to get hold of her for my mom 50 birthday, I couldn't I tried with all my contention. Nothing. My mom use to work for Up Pretoria, she got all the child fees money. And her dad found out my mom had sanlam policy now he claims everything. What about me and my brother, that's our mom to. She's not on the policy. .. what can I do in this case. I did go to police station and write a police report. Sent it to sanlam. Jo Ann Bothma Jan dad "