child support and visitation are considered seperate under the law. you cannot withhold one for the other.
mother could find herself in court for contempt of court-denial of visitation. if you do it enough times you can lose primary custody.
the proper way to get your child support is to take HIM into court for contempt-lack of child support. And let the judge handle it.
And the even bigger issue-the ONLY person you would really punish by denying dad visitation this way is the child-who has no idea, court orders for anything even exist-which is as it always should be.
"It is easier to build strong children than repair broken men." Frederick Douglas