Debt collection — National Credit Systems,Inc. (IL)

Impersonated attorney, law enforcement, or government official. a electronic signature is not validating proof of claim, and sated before, there is no proof stating that I owe NATIONAL CREDIT SYSTEMS at all, a guy name XXXX called aggresive, over the phone and called before XXXX central time, that's harrasement please show proof or a contract stating or bearing my signature that I owe them ( national credit systems ) How can a third party collection agency not know what state I live in at all.