That thread is loaded with remarks about what sounds like South Asian payday lending thugs.
http://800notes.com/Phone.aspx/1-888-311-6369/10

If I'm right, you won't have a place to send the cease-communication letter I'd routinely advise at this point, much less an address you could serve a summons for the hostile call pattern described.

FTC and CFPB material on US federal collection law:
http://www.ftc.gov/os/statutes/fdcpajump.shtm
http://www.consumerfinance.gov/askcfpb/search ... debt-collection

I received a call from his number asking for a Janet Richardson. I don't even KNOW a Janet Richardson! They must be working with the number 888-311-6369 because they call and ask me the same thing! They spam my phone with calls... 4 in less then 5 minutes!