This sounds like debt collection, or perhaps we should say extortion dressed as collection. Could be the usual US lawbreaker or a fake collector from South Asia. Try to get a business name and share it with the readers. By federal law this name cannot be withheld.

On 800Notes in the ''Debt Collection Calls'' forum is a thread titled ''Fake payday loan collection scams - Please list new numbers here [2]''. My notes and advice on the payday loan collection thugs, updated Oct 2011, can be seen on the lead page.

The following will be useful if you have a US domestic collector calling:

official FTC guidance and staff opinions on the FDCPA, PDF copy of the Act

CFPB reiteration of the Fair Debt Collection Practices Act
 Oct 04th, 2012
Caller said his name was Alex Smith, and he was going to have me arrested tomorrow. He could not speak English fluently to understand. I have called back and got a voice mailbox.
Marie thornton
 Oct 04th, 2012
i just received a call from the company said investigation something and i found out this as scam from fbi. i report it to my local police and i just make them fool. yu........ooohhhhhhh.................hooooooooooooo
 Mar 02nd, 2012