Sue for child support overpayment

It is possible to sue mom, but you will look like a heartless B*****D in the eyes of the court. DSS will not accept responsibility for their goof up and will claim they do not have the means to re-coup their money. They can garnish your paycheck without any problem, but somehow, they can’t get overpayments back by using the same method.

my son graduated May29th of this year.Dss did not stop my child support as it was supposed to and i ended up having to hire an attorney to get it stopped.I over payed 2 months worth of child support and she of course kept the money.Can i sue her for the amount
i overpaid?