I was supposed to receive $1875 federal tax return and I never got it I got the $92 state tax return but I never got the federal tax return

I owe child support then they sent my ex-wife the $92 state return but they never sent to the $1875 check federal but last year September 17 I paid her off all the money that I old her all the reasons that iota so I was obviously that check is supposed to be is supposed to come to me now so the check is missing right now