Child support may not be garnished. Is someone trying to do that?
This is legal. There is a difference from garishing bank accounts and garnishing child support. They are levying your bank accounts, and that does not distinguish immediately the difference between chlid support or not.
You will have to get a temporary injucitinon agains the levy, and petition the court ot intervene, be proving the money is child support and not earned income. The court can apportion the levy.
Unfortunately, it will take an attorney to be successful.