statute of limitation

Received a call today from a Mediation service for Advanced America, a payday loan place. I had a loan through them in 2004. They said I owed 917.10 but would drop it to 600.00. I don't understand where the 917.10 comes from as I never borrowed that much. My bank closed my acct for overdrafts either before or after the check was sent through, I am not sure. The mediation place said no court case has been filed as of yet. I am on a fixed income and can not afford 600.00...How do I find out if this particular debt is beyond the statutes of limitations. I have been online with attorney generals and looking up time-barred debts for a while now and am confused as to how to go about getting the exact answer..

Any help is appreciated
Thanks Sunny