Bronson and Migliaccio

Trying to figure out the best course of action for the predicament I am in.

As a freshman in college I, stupidly, signed up for a credit card with CitiBank. I maxed it out and only ever made one payment on it. About 4 - 5 months ago, after seeing that I had nothing on my credit report from CitiBank, I called them to find out what I owed and how I should go about paying the balance. After looking me up with the old credit card (which I still had laying around, miraculously) and with my SSN, they said that they had no record of me or what I owed and to count myself as lucky. Not one week later I received a phone call from someone at Bronson and Migliaccio. I never received any sort of letter from them, though they are claiming they sent one in September. They demanded payment in full, which I told them I was not able to do. I told them that I would be willing to make payments, but only after I received a letter in writing from them about how they came to own my account, what I owed and proof that I owed that amount, and a letter in writing about the payment plan. I have received nothing. I have also been switched to a different person than the one I was originally dealing with. I have been threated with having "litigation" brought against me.

What should be my next move? I do not mind paying the debt, I do know that it is owed, but I want to make sure I am not being scammed! Should I send a letter asking for validation of debt? A cease and desist letter? Should I get an attorney of my own?

This is my first and only time dealing with a collection agency and I don't want to get burned, as I've read so many stores of people paying twice what the owe and such.

Thanks in advance.