How can i obtain my portion of surplus funds from my deceased fathers foreclosed home .

My sisters signed a contract to receive funds from some company that reached out to them ,I did not sign it I was not comfortable with the language or the percentage firm requested.I was told by them my decision would not affect my sisters and I could request my portion on my own..Not sure where I should start the process.A refund was received according to my sisters and they are now waiting for payment.My concern is how do they know they are getting the right amount if they never see in documentation of what total refund was.