What should i do in a situatioin like this.?

what do you do when children doesn't want to see their father or go over to his house. i have been seperated for 1 1/2 years and in the process of a divorce. he doesn't iinact with them. they told him why they don't want to go over but he blame me . i left him for men tal abuse with me and all the things he is talkiing it ot on the achildren. now he has not contact with them and tell his lawyers that i am the cause. but there are happy not going over there.