Social Security Offsets from our tax return please help!?

Ok here is a little history, my wife was receiving social security from her mom before she turned 18 she was also working at a fast food restaurant and made slightly more money then what she was supposed to. After she turns 18 we get married and social security takes $1800 from our tax return that year. We go to the S.S. office and they tell us that we are paid in full... This year they completely seize our tax return again and when we called the 1800 number they tell us they have no record of them taking the money. I am soo pissed at this I can barely type this question. If the main 1800 number has no idea what we are talking about how in the world are we supposed to go about this whole ordeal? If there is anyone who knows anything about this corrupt government organization that can shed some light on this please help because we really need our money back... Also, we were not married when she accrued this debt also the 1800 number has no idea how much we owe to them either.