Called only once, on 12/27/16, but had penetrated our work automated switchboard, maybe using a random number to get to my extension. Message left was just a lot of background chatter. Added number to my cell phone's junk call list, just in case.
I finally answered after weeks of multiple calls per day, no messages, and unable to reach the number when I called back. This was for Material Handling & Logistics magazine wanting me to sign up for a subscription. I told them to not call me back, we'll see!