The main number for the ongoing "payday loan" collection scam. Variously self-identifies as a law firm, collection agency, law enforcement (often the non-existent "FBA"), or a combination of all three. They use various lies (threats of lawsuits, jail, etc.) to intimidate people into paying them large amounts of money for defaulted "payday loans". They may even have a potential victim's persona info, because they're purchased (or stolen) it from another company.
This is not a law firm. This is not a collection agency. This is definitely not law enforcement. Because of their heavy accents, these clowns most likely are not even in the U.S.
The listed carrier for this number is Ymax Communications Corporation. Ymax is the company behind the "magicJack" VoIP device. A magicJack can be used anywhere in the world where there is a high-speed internet connection.
My suggestion? Cut them off and let them know that you know it's a scam, and that you'd really like to listen to their scam, but you're busy eating a big, juicy hamburger. Or say the F-word a lot. Then hang up.