They called my very private cell phone number at 10:21 AM PDT on 7 October 2016. The caller ID said "Briggs, TX". I did not answer. They did not leave a message. My phone numbers are on the Do Not Call list. I will report them to DoNotCall.gov.
Never call them back, not even from a blocked phone. They have ways to unmask your phone number even when it is blocked.