Petition Cap the amount payable for child maintenance

CSA 1 child payment= 15% net income
CSA 2 children payment= 20% net income
Child benefit payment= set amount capped by government.

How can it be that one government department can set out a clear amount of money to support a child (Child Benefit) and another thinks its ok to bleed a non-resident parent dry? Non-residents are in a no win situation. The more you earn then the more you pay. Yet every family receives the same amount in Child Benefit.
Child maintenance payments are crippling non-resident parents. This payment comes before all others! Not all parties are willing to set up private agreements so the agencies help to mediate. Now we are told they are going to charge 20% to take money from paying parents.
This has to end! Where is the justice? Why can't child maintenance payments be the same as those for child benefit?