If hes not going to be there next week, I would refund the money.
As for the baby, I would just cite termination as not fitting in to the daycare. I'm sure someone can help you word this better, but I would put that dcb is terminated effective immediately due to the safety of the others, and that the baby is terminated with the usual two week period and the last day will be XXX. If they want to pull the baby out immediately, then they forfeit their deposit for that as well.

Reading what Blue Rose wrote above me is perfect. I would use that.