I got a call from this number, didn't answer, no message.
If you've got an iPhone, look at your recent calls. All the way to the right of this number is an "i" in a circle, click on that, then scroll down until you have the option to "block this caller". Then block 'em.
Other cell phones probably have something similar, if it's your house phone, check with your carrier about blocking certain number.
Damned bottom feeders. Called my donotcall registered number, left no messsge. Returned call led to 'this is not a valid number' message. Reported to donotcall.gov website.