I got a call from this number and they hung up after 3 rings.  I was not able to answer in time.  In general, I get lots of telemarketing and scam calls on Mondays (which today is a Monday).  My search on the Internet and Spokeo give me no additional information and when I called the number back three times, the line was busy...

This number has been calling me for the past two weeks.  I answered once by mistake and they were calling regarding Principal Advantage insurance.  I have been letting this number go to voice mail when it is identified by caller ID but they never leave a message.  Any suggestions on how to get it to stop?  I am registered with Do Not Call.