Get Sheba home

The Humane Society took my dad's dog after he died and won't release her. I'm out of state but have transport ready to bring her home. But they say - no I must adopt her and pay everything my father did years ago. They say he signed a contract that if he could no longer care for her she would be brought back. But we want to raise her as were my dads wishes! Shouldn't they want Sheba to be with her owner's family and have a great home with ones that love her!!??