My son needs counseling-ex husband refuses, HELP !!!

I live in Delaware. My ex husband has placement of my two sons during the school yr and i have them in the summer. My oldest son who is 8 is in need of some counseling,he is mad at me all the time and completely defiant. Of course as we were in a nasty custody battle i certainly dont doubt that my ex husband fed him some awful things about why mommy and daddy arent together. I had him all summer with no problems, now all of a sudden right back to square one so i arranged for counseling for him and I since my ex claims he doesnt have a problem with him and after putting all these restrictions on me about taking him (like i have to do it on my time and he wont take him and i cant interupt soccer practice etc) now he says he wont agree to it. SO what can i do other than file a motion with the court (takes 6 wks here), take my son and let him dispute it with the court or am i in my rights as a parent with joint custody to take him??? It seems almost as though my ex doesnt want something to be uncovered in counseling or something -he is so adamant that he not go and i am the one who needs to go etc etc.
Please help. thank you