He won't give my kids back

He won't give my kids back his mother was supposed to bring them July 30 after 2 weeks but they didn't. We have 50/50 custody agreement since January I called the police and filled a report, tried to reach out to the judge but nothing it's been almost 7 weeks and he said was the kids didn't want to come home to me then later said I could get the kids back if I get him back and he won't even answer my call or text or anything anymore same for his mother. I don't know what to do I don't have the money to get a lawyer and I still own money to my last lawyer and he was the only one willing to work with me because most lawyer in our area have connection with my husband's grandfather. Honestly I don't think I will ever see them ever again if I don't comply.