Alvin tears the second contract, and lets the pieces fall, disappointed that the devil is playing so true to his nature. Alvin knows he doesn't understand the first contract fully, and the nuances are lost on him.
"You know that is not what I meant, Duke of Cania. I do not bargain with souls. This contract with us is not like those you have always made. You want to leave this place, and I have given you my word that I would do what I can to accomplish that, if you let us pass. That should be enough for you, given that we are the best hope you have had to leave in some time." (Here Alvin gestures at the zombies around the devil.) "You surely have sufficient magics even in this place to know that, by Lathander, I am speaking truly."
"You say you have an item that can help us, but you will not say what it is. More games. If you present it to us now, show us what it is that may help us secure your freedom, now that I have given you my oath, we can consider this..." He waves the initial contract he had been presented. "The truth is you want your freedom again, and your not agreeing to let us pass is nothing but stubborn pride."