My question involves collection proceedings in the State of: TN

I got a Summons to appear in General Sessions court being sued by NCO Portfolio Mngt.

Says it's an old Citibank credit card. $3378.71

Nothing of the sort is on my credit report.

Summons says to answer and I read online about answering. I called the city clerk and they said I did not answer except on the day I go to court. That I cannot turn an answer in. Is this correct?
I sent a letter to the Lawyer (debt collector) requesting validation of the debt.

Any advice at this point?