Petition the court to enforce the order.
Legal disclaimer: In accordance with the Avvo community guidelines, this communication does not constitute "legal advice", nor does it form an attorney-client relationship.
You can file a Motion for Contempt and/or Motion to Modify Child Support IF there is a 20% change in the amount of child support he should be paying to you since the divorce decree.
This answer is for informational and educational use only. This answer does not create attorney-client relationship. For more details, I recommend a private consultation with a family law attorney. Stange Law Firm can offer you a free one hour consultation if you call (314) 963-4700.