Can you contest a beneficiary and win?

My dad passed away on 1/31/16. We called to get his policy cashed out to pay for his funeral. We found out the policy was never changed from his brief 13 mo marriage with a woman after my mother. We sent in his divorce decree and settlement into the insurance company, only to find out that there are secondary/contingent beneficiaries. They removed the ex wife per the settlement agreement, but HER grown daughter, and my brother, my dad's son are 50/50 on the policy. We have no money to bury out father, but this policy. He had nothing. Is there any way to fight this? He was not good at finances and believed everything was taken care of when he went into the hospital. We are trying to contest it. If we go to court, what can we do? We have an attorney involved, but are there any insurance loopholes that we can use? We are writing a letter contesting to the insurance company. If the ex wife is removed, why should her daughter receive the funds? The previous policy, that we have, has all of his children on it. They are not acknowledging that one. I realize it's a contract, but is there anything we can do to fight it? We need to pay his bills and grieve. Thank you.