There is a radio program from Los Angeles called Handel on the Law, hosted by lawyer Bill Handel, on KFI radio. The show is on Saturday mornings 7–10 AM PST.
Bill Handel also has a website where you can search for a lawyer, of the type you need, which would be in the categories of Divorce, and Family, and Children/Child Support.
You and your ex husband do not need to be in California to get the free referrals to lawyers in your area, and as I understand it, the first consult with the lawyer that you choose is free so that you can ask how to proceed.
You can try calling into the show, but you can also email Bill Handel and ask for assistance in how to proceed.
All of the lawyers on his recommendations list are vetted.
Here is the contact page:
http://www.handelonthelaw.com/ask-a-lawyer/
Here is more info about the site, and the menu is up in the top left corner:
http://www.handelonthelaw.com/about-us/