Caller Id says Startel, LIC

They are checking to see if i am alive. I called them back as they didn't leave a message and they refused to answer my call and disconnected on my second ring

calls , no message

I keep getting calls from this number and they do not say anything.  When I call the number back, it states that the number is not in service?  If that is the case, how does this person keep calling me from this phone number?

I called the # and it was a recording asking if I want to lower my rates for electricity?  At least it is a working # ?!