keeps calling robo number

This number calls my house often, normally three to five times a week. My husband works third shift and we usually keep the phone ringer off, but I finally answered when they called today and no one was on the other end, just silence.

Ignore this number! :)

I get calls from this number one to three times daily.  Always silence.  I reported them to the National Do Not Call Registry.

recd this call a few times so i finally decided to call back.  it states (male semi hispanic automated voice) your call is very important to us and will be transferred to the next available agent.  (female automated voice) your call is now first in line and will be answered by the next representative and  your current wait time is 15 seconds.

keeps stating that and its going on 3 minutes...lol   got tired of listening to it and hung up

Just received a call from this number.  The woman was very difficult to understand.  She asked if we had a copy of our last electric bill from Duke.  She said that she wanted to give us a rebate, but needed some numbers off the bill.  If Duke wanted to give me a rebate, they would HAVE all the numbers!