Sweetheart move house, as far away as you can, don't give him a forwarding address, get a guaranteed next day delivery envelope from the post office, rip the one end so it looks as though it's been accidentally damaged and the contents have fallen out, keep the slip filled in with his name and address on it. The PO will deliver the damaged envelope to him ( water damage looks best) and you will have proof that you tried to inform him. If it comes to court again, it will be in a new area with a new judge, but he'll have to find you first. This is what one of the girls who works for me did.
If you make travelling to get there very very difficult for him, and then refuse access once he's there on the grounds that the child is ill, it'll cost him a fortune, inconvenience him and hopefully he'll give up.
Don't take this lying down, make it difficult for him.