caller left the following message: dial-tone, then "If you'd like to make a call, please hang up and try again. If you need help, hang up and then dial your operator. If you'd like to make a call, please hang up and try again. If you need help, hang up and then dial your operator... followed by off-hook tone to the end of the message.
whitepages dot com reports:
Owner's name hidden by Whitepages for privacy reasons
Owner is based in Amarillo, TX
VoIP - Level 3 Communications (NONFIXEDVOIP PHONE)
number is now blocked

Sounds like someone used the conference-call ability of a business PBX to connect that message to another number. I pulled pranks like that ... long ago when I was young.

Called twice in a week.  Unsolicited.  Have received numerous calls from wide variety of numbers in the past two months.  This is new.  Never had problems before,  and am on the "no call list."

Calling at least 2X daily.

Calls multiple times each week.  Never leaves a message.  I answered once to ask them to take me off their call list and they hung up immediately.  Then called again a few hours later.