Enlist the help of your county attorney's office and any other county resources that are available to you. The county attorneys are often very helpful, and are frequently involved in child support matters, particularly if the party receiving the support receives assistance from the county.
Get a Judgment
In some ways child support is a unique kind of debt. In other ways it is not. Find out the requirements in your jurisdiction to get a child support judgment.
Collect Your Judgment
Once you have a judgment, there are a number of collection mechanisms available to you including earnings garnishments, non earnings garnishments, and levies on assets.
Motion for Contempt of Court
You can motion for the payor of the child support to be held in contempt of court if they meet certain requirements related to the delinquency of the child support debt. Then, the court will require the payor to explain himself/herself to the court and explain "why they should not be held in contempt." A payor is given a chance to "cure" their contempt by meeting certain conditions. If they do not meet the conditions set out, it is very serious, and could result in jail time for the payor.
Many jurisdictions have a process by which various licenses can be revoked for the non-payment of child support. Professional licensing boards may also have relevant rules or regulations. Driver's licenses, professional licenses, and hunting licenses are all potentially in jeopardy. Consult an attorney to discuss your options.