Did not answer, no message. I hate these calls. I wish the Do Not Call registry could fix these calls too. I don't take any calls I don't recognize the number for. If I get a valid message, I'll call back. Kind of sucks for my real estate business, but I get so many unsolicited calls I have no other options.
I have a smart phone and got an app ( for free ) that will block calls that are not on your contacts list. and it works. It may show up as a missed call, but it won't ring.