Hello, If anyone is willing to help.

I have a debt with a CA on my report that shows a DLA of 11/2006.  The SOL in my state is 6 years.  I truely don't recall the debt, and the creditor JUST started calling.  I stated during the call that I don't recall the debt and they came back with the "don't give me that" line.  They did have a valid last 4 of my SSN.  

Anyway, my question is, should I send a DV letter?  Should I send a C&D?  I don't want to reset the DLA since the SOL is up, and it will fall off of my report in another year, but I really need it off NOW.  Any suggestions?