I've long felt that Admin's stock advice at the footer of each thread page is misleading. There is no ''one size fits many'' approach to every category of mystery caller. Call blocking is a purely reactive response which muffles the noise but does nothing to cut off the callers at the knees. Most devices soon become overwhelmed as the junky callers rotate and spoof their phone numbers. What's more, many callers reported here are exempt from DNC list scrubbing.
The credit reprice scammers are certainly covered, but these are career criminals we're talking about here. They've weighed the risk of lawbreaking and it is simply too low to stop them. The wiser scammers dance ahead of efforts at control as a natural part of their business model.
Complaints to DNC are helpful in only a passive sense, adding to a pool of intelligence which is useful when regulators and law enforcement take action. This function is explained right on the DNC website. I would suggest not confining your complaints to a single channel. Give your story to the FTC, attorneys general, and the (however toothless) BBB. In 2010 the FTC drew upon all these resources to shut down several ''Rachel'' and ''Heather'' boiler rooms. I would even try the Secret Service, per its mandate to investigate all sorts of financial and electronic fraud.
Complaint filing is vital for the greater good but not likely to bring a swift personal solution. The next level I see is a theory of ''death by a thousand paper cuts''. If by a long shot you can nail down a physical U.S. address for your caller(s) or its HQ, then you can consider a lawsuit under TCPA and/or UCC and any relevant business regulations. The incessant bot calls to mobile phones are worth $500 a pop, or treble damages after the caller gets a Cert-mailed cease-comm.
You can't catch a devil if you can't find it, but these thugs are not invisible. Many ''Rachels'' historically appear to operate in phone scam capital Florida, for instance. Others may deploy overseas call centers, but could have someone stateside ripe for beheading.
- further reading -
Telephone Consumer Protection Act
Various laws in brief from the FCC
US Secret Service investigative mission