Nothing that you do will stop them from calling you. The major players behind this have made millions of dollars, which means that they are too big to fail.
One of the major players specializes in aiding the rich with tax evasion and shell corporations set up in Belize. You can bet that the well to do in this country are not getting lower your credit card interest rate calls and due to that fact our government just considers a few phone calls a minor annoyance.
The FCC has temporarily halted 5 of the minor non profitable boiler rooms. They will receive a slap on the wrist and be back at it within a few days. In the meantime the calls will continue since the major money is being made with what is called a CNAM revenue-sharing program through companies like http://www.telephonemanagement.net
In their own words: Every day your company makes thousands of outbound phone calls. Every one of those calls generates revenue for many companies, why not yours? Our CNAM revenue-sharing program helps you make money every time a Caller ID request is made by a phone carrier. A high-traffic call center can lose hundreds to thousands of dollars a day to phone carriers by allowing them to charge for access to your own data.
You can now see why the criminals keep calling even though they know you won't fall for their scam. If someone does make the mistake of answering the phone and falling for their con then it is just icing on the cake for them. These people are the lowest form of filth on this planet. The only way to stop this is to contact the FBI and ask why this crime family is allowed to operate and facilitate the ongoing criminal operations. This is one of the reasons that the RICO act was put in place, so why aren't they using it. Is this because this isn't a high profile, news worthy operation or is the FBI too understaffed and busy with Homeland Security issues. Maybe if we were rich they would take this seriously, but then if we were rich we would be using that criminal organizations services and protecting them instead of trying to shut them down.
There is a blog site that has information on one of these operations: http://telemarketerspam.wordpress.com