Who should I contact about State back taxes from 2004/2005?

I received a letter from a representative of Ohio Dept. of Taxation stating I owe the state $3448.85 in back taxes for 2004 and 2005. I have always been told didn't have to keep this information for more than 7 years. I just shredded those two years not 3 months ago. I have called the IRS, my place of work in those 2 years, and the representative for Ohio. I can't find anyone so far, that keeps the information for that length of time. What can I do or who should I contact about this. I have until Sept. 5, 2012 to get this taken care of.