Your phone number doesn't need to be listed to be called by an auto-dialer. You can report calls that violate FCC regulations on the FCC's website. The FCC usually doesn't do anything directly, but they track the complaints and, if there's a sufficient number of valid complaints, AND they can track down the spammers, they will pursue it. However, seeing most of the violators are also scam artists who don't give a flying rat's behind about the law AND they disguise themselves by using VoIP, spoofing their phone number, etc., it's hard for the government to track them down. I report them anyway because no one can do anything about it if nobody complains in the first place.
Some butt-wipe trying to spam my fax machine, which we leave turned off for just this reason. It's pretty ballsy when the scammers and spammers want to waste your money by using your machine, toner, electricity, and paper to try to swindle you into something.