Stop unfair child support backpay

I want to make a motion to abolish child support backpay. Imagine you have a child with Some one and you do everything in your power to keep things together but after a year n a half or so you split up. Now child support gets involved, they sit you down and tell you you owe $2,500 for a tanif bill that the other parent received. Then they say you also owe $350 for every month, your child is 18 months old so that is a grand total of $8,800. Now ask yourself, is that fair? Even though you are also supplying everything your child needs on top of child support