This number calls me all the time. Usually I let it go to voicemail, today I answered and a recording told me that "Card Services" wanted me to press 1 to reach an operator to discuss my account. After about 12 rings a man answered, "Hello" and I asked "What company is this?" He said it so fast I couldn't understand him, then launched into his spiel. I told him I didn't have a credit card with his company and that he was calling an unlisted number and I'd like to be taken off his list." He told me I deserved to get these calls and hung up on me.

FTC #1 criminal according to LA Times Article: http://www.latimes.com/business/la-fi-lazarus-20140107-column.html

But, still the govt cannot get them under control.

You can also block these numbers using an Android phone.  It works on my Samsung Galaxy, you just "Add to reject list"

Got call on cell phone. Didn't answer and no message left. That way they won't know if it is a "live" number and sell it to scammers.