Sadly, in child custody and child support situations, too many parents makes mistakes that the law does not permit. If there is a problem collecting your child support, whether its late or in arrears, or about to be attempted to be lowered, you CANNOT withhold access to the children from the support payer. And if access to your children is withheld or denied or interfered with, you CANNOT withhold child support. These are two different issues at law.
In Family Court, child custody and visitation is heard by a Judge, whereas child support is heard by a Magistrate. This alone should tell the least informed that they are two different issues and that access to the children is more important. Sadly though, the law often addresses child support issues as being the most important of the two. Let me prove this wrong.
Poor families without much money but a lot of love, guidance and affection from the parents produces healthy and happy children. Children from wealthy families where the parents have no time for the children and merely leave money on the kitchen table for the children after school but no guidance, nurturing and affection from the parents often produce very problematic children with serious emotional and/or social issues including drugs (of course better quality drugs because they can afford them).
So, what is most important for your children if you truly love them more than you hate the other parent? Ensuring and encouraging access to the other parent and encouraging that relationship. Do NOT take self-help, go to Court and file an application for the Court address the problem(s) in accordance with law.