Debt collection agency. The truth about debt is that it does not exist by the time it goes to collections. Who you originally had the debt with has sold that debt for pennies to the collection agency who collect it from you with interest. Deny who you are, don't answer any questions.
Whoa, there, Vanessa.
Your "truth" isn't true, from a legal standpoint.
Sold debt still exists, but the "debt collectors" who make these calls and claim they have a right to collect that debt have to prove the debt exists and that they have a right to collect it, and that information has to be sent in a letter to the person they are trying to collect from, using the US Postal Service.