M.C.
My ex was a crazy narcissist who threatened, stalked, and intimidated. Whenever he involved the police, I would calmly and politely tell them that he wasn't taking his medication for his bipolar....it drove him mad and stopped the baloney. The best thing you can do is get court orders regarding custody, visitation, and child support. You can have your attorney specifically write in the court order exactly when the child is to be picked up and dropped off and even when he can have phone contact with you regarding the child. There are so many things you can have written in these orders so that you have minimal contact with him. It may seem like forever to rid yourself of him, but eventually he will move on if you do not cater to his drama.