Very helpful! I was scared out of my mind. Joseph Allen contacted me and used a different number 720-437-7020 stated he was calling from MI.

On my attorney's advice, I opted for the second option I was given to turn myself in once the affidavits were filed.  Of course, there's nothing.
1.  NO ONE can file federal charges against you unless they are a federal prosecutor.  They can file a complaint, but NOT CHARGES.
2.  BEFORE ANY CHARGES are filed, a federal grand jury must hand down an indictment.  If this is happening, you will most likely know (not always, but more than likely.)
3.  a federal prosecutor will not convene a federal grand jury for small amounts like this!
I know I may be giving away some things that these people may not be aware of (including federal charges not having "classes"), but this only means that in order for them to continue to use this kind of scam, they'll have to come up with new scripts and much, much higher dollar amounts which anyone would certainly check out before sending tens of thousands of dollars!
I hope anyone else that hears from these people check this number out or get to this site because they scammers are using new, similar numbers.  Everyone needs to be aware!

Please file any reports you can.  State attorney, local (if they threatened to come to your house or send someone... my local department took the report because they were dumb enough to leave me a voicemail!), FTC and FBI (they also have a form for this.)  If you were provided an address to send money too, look it up.  It's probably a mailbox store.  Tell them scammers are using them.  I did it and I also called the Sheriff in that jurisdiction and gave them the details.  They couldn't take an actual report over the phone (swatting reasons) but if you file locally, they investigate with a request from your local department.

I have not filed anything yet and YES they did leave me a voice message.

I got a call from them saying i took out a loan with advance cash for 550 but bounced a check for 850 but will have to pay 1