'Complain' in the Bible

It shall be, when their fathers or their brothers come to complain to us, that we will say to them, 'Grant them graciously to us, because we didn't take for each man his wife in battle, neither did you give them to them, otherwise you would now be guilty.'"

"Therefore I will not keep silent. I will speak in the anguish of my spirit. I will complain in the bitterness of my soul.

I remember God, and I groan. I complain, and my spirit is overwhelmed. Selah.

Why does a living man complain, a man for the punishment of his sins?