Dept of Education Student Loan

Graduating and voluntarily repaying, I continued graduate school under deferment. Subsequently, discontinued payments, supporting grandchildren, but NCSEAA sold my loan (package), after 120 days, default. Since, no longer concerned, NCSEAA told me to borrow the money and pay off loan, their logic was it's cheaper than the 25% fees they'll get if I don't. Now, in default, which I'm not because my payments are voluntary, since I'm still in graduate school with deferment; I'm ineligible for consolidation, lower interest rates, and public service debt forgiveness, law enforcement POST certified chaplain. In one conversation with NCSEAA, a moderator spoke with me, telling me I had a valid claim, and it would be resolved. Not hearing anything, what did that mean, phone calls not returned. Now, I received a collection from Enterprise Recovery and called the Dept of Ed., and told collection recalled with referral to Collections in Texas via letter. What do I tell them? How do I explain? What do you recommend? Ideas or suggestions? l am thankful for my education, but the fees, charges, who knows what, doubles my original loan. I've even had tax refund claimed by some agency with no credit against debt indicated. My annual net earnings averages less than 15,000. I'm at a loss. Is there no one who can help?