Anonymous above has the right idea, but I'll add to it a bit.
On 8/13/12 they called from 971-220-1784 as LOWER INTEREST. On 8/22/12 they called from 503-902-8480 as LOWER INTEREST. On 9/5/12 they called from 305-587-2165 as CARD SERVICES. On 9/22/12 they called from 407-476-5700 as CARD SERVICES. Exact same recorded message that you've all heard so many times.
Whatever name and number they use, if the numbers are spoofed, then the phone companies should set up a system that verifies where an incoming call is coming from. They have the technology. Ever hear of 900 numbers? If they can't ID the call, then they block it. The fact is that the phone companies are making money from these scammers, so they have no reason to cooperate in shutting them down. The FCC is just plain too slow.
It would be great if the numbers that they use would be broadcast on television so that most people would know not to answer or interact with these people in any way. Stopping them from making money would shut them down faster than anything else.