Also known as "Rebecca Outlaw", which to me is much closer to the truth.  These are extortionists trying to scare you into paying them money for nonexistent and imaginary debt.

Read up on your rights here and also make a complaint at this government site:  http://www.consumerfinance.gov/

Also file a complaint with your State Attorney General's office.
List of State AG’s offices:   http://800notes.com/faq/attorney-general