Debt validation question

I sent a debt validation/dispute letter to a collection agency who is trying to collect $5500 on an account that has been inactive since early 2003. Today, I got a letter in the mail from the original creditor which included copies of a few unpaid bills from early 2003 and a copy of their customer agreement. The letter states that "a copy of the original application was not available, which indicates this account was applied for by telephone or internet." Does this constitute validation of the debt? My understanding is that the collection agency, not the original creditor, was to respond and send me information showing how they calculated the owed amount, proof that SOL has not expired, etc. Also, I had moved to a different state, and then moved back to the state where I live now. Will this affect the SOL for this account, which should be expired? If I bring that up in court, can the creditor get a judgment if they claim they were unable to find me during that period (I have been living here for 3 1/3 years)? Thanks for any information!