NCO Financial

I have gotten a letter from NCO requesting income info for my student loan. I provided them with the info requested and the held a "hearing" which stated that it would not cause financial hardship to garnish 15% of my disposable income; however, the amount they have as my monthly income in not even close to what I make. I only bring home $580 two times per month and have 3 children in my home. When I called them to report that my income had been calculated incorrectly, I was treated very rudely. I offered to set up an alternate payment arrangement with no success. They stated that I could either pay $378/mo or it would roll to garnishment. I tried to explain that I do not get paid until the end of the month but he said he didn't know if it would wait that long. I want to repay the debt but I can not pay what I can't afford. I have to take care of my family. The letter I received from that stated that I would need to sign and return a repayment letter within 10 business days, but when I called them yesterday, they said that it would not go out until sometime this week. Can anyone PLEASE HELP? I don't know what to do.

Who is the guarantor for your account? You might wanna call them or the student loan ombudsman. A garnishment would only get them $174 per month....I dont understand why they are going for higher.