Stop new Child Maintenence Service going by Gross income instead of Net income.

How can the new Child Maintenance Service justify going by gross income instead of net income? How can us fathers pay for our children with money that we do not even receive? I'm all for paying for our children but adding 20% charges on top if you use the collect and pay Service? Not all families have the luxury of their child's mother being co operative and will force you to use CMS. They don't even consider your monthly expenses such as mortgage etc. Please help and get the government to stop this ridiculous change before we all end up homeless and jobless.