State And Federal Tax Offset

I have not received a dime from my ex-husbands tax offset but he did! He sent in 4 years worth of Fed and State taxes (2006 - 2009)I have not received any of his tax refund (offset) But he has already received a check from Iowa State Treasury for $455 for 2006 and $526 for 2009. This man owes me a total of $10,000 in back Child Support, how can the state issue him a check and not give my anything.

I called Child Support recovery unit and they don't see any money coming my way. My case worker informed me that his Fed 2009 for the total of $1,411 was kept by Child Support Recovery for when I was on FIP 6 years ago. $126 is still outstanding for FIP. So my question is where are the 2007 and 2008 Iowa checks and Federal 2006- 2008? Child Support Recovery will not answer me and Iowa Dept of Revenue and Federal will not either.