I'm guessing you have talked to the mother about working with you to get a routine going. Is she even trying to do that? If both of you work on that and it can't be done, he probably needs to be looked at. If she doesn't care about a routine, even after you explain to her that a routine is important for the child, cancel the contract, unless you desperately need the money.

As far as trying to soothe him, I've heard of things you can get for babies that make a heartbeat sound. Maybe try one of those, or something that plays a nice soothing music.