defaulted Unsub-Career Training Loans

I'm hoping that I can get some helpful information about my Career Training loans through Sallie Mae. They are private loans that I took out while attending Remington College in 2005-06, at the time that I signed the Promissory note I admit I did not understand that this specific type of loan is not eligible for deferment or forbearance. At first, when I had a decent paying job I was able to make the payments, but I went back to school and no longer had a full time job so I couldn't afford the payments. I called Sallie Mae to request the loans be put in forbearance/deferment and was told there was no problem, only to later get a past-due notice in the mail. So then I called Sallie Mae to straighten it out, and they informed me that my career training loans, because they are private are not eligible for deferment or forbearance. At that point, I went into default quickly because I did not have the income to cover the payments. I was also unemployed for a period of time after receiving a medical discharge from the military.They forwarded over my account to a third-party collection agency called Allied Interstate, where I entered into a payment plan of approximately 300 dollars per month for a period of time, then I would be able to get reduced payments and reduced interest rate. However, after doing some research I found out this collection agency had actually been sued for illegal practices! So I stopped the payment arrangement and have been making occasional payments directly to Sallie Mae online. They have been accepting every payment I make towards these Career Training loans. The other day, I spoke with another 3rd party collection agency to which my account had been turned over. The lady I spoke with was nice, but kept trying to push that I should borrow money from a family member to make a payment of some outlandish number and then I could enter into a 0% interest repayment plan with them. I told her that I do not have any family members willing to lend me such a large amount of money. So she said she had another payment option and wanted me to fill out the application with her. So I gave her my income information, let her know that my wages are already being garnished for another debt(probably not the smartest thing) and my monthly expenses. So she puts me on hold and her supervisor gets on the phone.This guy somehow calculated that I have 700 dollars unallocated per month, and proceeded to talk over me, make accusations about my character, said that he was going to write it down in my file that I refused to make any payment arrangements, he would call my employer to verify how much money I am making and then would pursue me legally to have me garnished for the debt. Does that company have the ability to do that? Can Sallie Mae pursue me for my defaulted loans even though they are accepting the payments that I am giving them? Where could I get a copy of the promissory note that I signed, strangely I am missing it-although I have all the paperwork for my other loans.I would like to see where in the paperwork it states that these loans are not eligible for forbearance or deferment. My credit is extremely bad, so taking out a loan to pay this one off is not an option-what can I do to avoid being sued?Any information you could give me would be extremely helpful!