Overpayment of Child Support Won't Stop

My question involves child support in the State of: California.

My daughter turned 18 in December 2011 and immediatley dropped out of school. Her mother has been receiving child support on time for the past 16 years thru CSS. She moved with my daughter before she was 18 and did not notify me, and she is aware that my daughter dropped out of high school and has not notified me but is continuing to recieve my month child support payment thru child support services.
I have phoned CSS many times asking them to contact her high school to verify that she no longer attends and the registrar sent back a fax early January 2012 stating that she is enrolled until she graduates in June 2012. CSS has said to me that they have made many attempts to gather this info on my daughter and the high school has not responded in the last 3 weeks. I have continued to call CSS almost on a daily basis to tell them that she is no longer attending high school and has now completed her G.E.D. I have 2 questions; How can we get the child support payments to stop immediately and how do I recoup the overpayment in child support?
Thank you.

If your order says that CS can be stopped upon her either dropping out of high school or obtaining a GED, then you need to file to modify (stop) the current order based on that. CSS won't drop it automatically.

It's unlikely you can recoup any overpayment.

It seems that CSS isn't taking my matter serious since I am the payer of child support, This has been ongoing since December 15, 2011 with numerous phone calls, why wouldn't I be able to recoup my money that is being overpaid to the custodial parent? It's not a few hundred dollars a month, it's a thousand dollars a month! CSS will do whatever they can to make sure that I pay but what about me? I've always paid and paid on time. Shouldn't I be entitled to recieve my overpayments back?

If you are absolutely positive you have no obligation to pay, file for a court date to get suspension. If you choose to stop paying, until court and are wrong, you could be in trouble.

CSS takes payments until the COURT tells them to stop. You NEED to get to court and get the order stopped.

The CSS isn't going to act off of phone calls, you need to file with the court to have the child emancipated. Honestly, a month isn't a long time to wait for this to be heard through the courts. Had you actually FILED, you would be closer to having child support stopped.

The only way you will possibly get the overpayment back is by suing the child's mother in small claims court and even then, it's not guarenteed.