Threaten me with lawsuit and arrest at my workplace. After I returned the call said if I purchased a prepaid card for $455 it would be settled out of court.I had no idea the account they were talking about

This is a criminal extortion scam operating out of India. They are making the calls utilizing VOIP and the names of legitimate firms to make it appear the calls are originating from within the US. There is NO "company" or "debt" and you will NOT be arrested. They are harvesting and/or buying consumers' personal identifying information and you need to do whatever you can to protect yourself. This includes: Notifying the FTC: https://www.ftccomplaintassistant.gov/, placing fraud alerts with all three credit bureaus, notifying your bank and employer and letting these criminals know you are aware they are attempting to extort money for a non-existent debt and have alerted the authorities.

They did not call me, but emailed me saying that I received money from American Cash Advance (which I didn't) and I need to pay it off or else I will be charged with fraud. I have filed a complaint with the Consumer Financial Protection
Bureau.

Rec'd a lengthy email from "Michael Black from Hogan And Hartson Associates"
They are going to file a lawsuit on my name stating that I am doing some fraud and Civil litigations.
I am going to be legally prosecuted int he Court House withing couple of days and my SSN is going to be put on hold by the US Govenernment.  They are going to notify my employer and I could be terminated if I am prosecuted.
So they have threatened me, my job, and my freedom.
I know this is a scam.  
I cannot deal with this any longer.

these people emailed my friend and told her the same thing and it was from Hogan and Hartson law firm they told her that she was going to jail