This dipwad said the same very same thing. (Very deep male, authoratative but also "familiar" sounding.)
Instantly hung up on him. Done with these bozos.
The bozos aren't done with you. They'll continue harassing you with different numbers. The criminals can't call you without a carrier. These criminals choose Neutral Tandem/Inteliquent because it's one of the few companies that support their scams for a living. Inteliquent will continue providing this scammer new numbers for you to continue blocking even after reporting it to them. Still report the call to the FCC and FTC, but do something about the problem as well. The method I've found that works is to complain to the Better Business Bureau about the other partner in the scam - Inteliquent in Chicago, IL. (1.866.388.7258)
Inteliquent will continue allowing the scammers to harass you because the scammers are paying them; you're not. Inteliquent is not a legitimate company or they would be able to make a profit through legitimate means without depending on the scammers.