Missing spirit after act 3

I did not receive the +30 spirit from using the item after killing the bog witch in act 3, still currently sitting at 30 max spirit.

What is a bog witch, and what is spirit? In act 3 you go after piety, and the act boss is dominus. There is no bog, and no witches. The sewers are kind of a bog, but the only things you do there is collection three busts to revive a skill point and you encounter an undying blockage, that you later destroy.