Who called from 2018200770

Left a message at 5:39am on Aug 19th saying that "Your request to be removed from our call list will be fulfilled immediately."  Nothing else.

Called my office just before 1:00am - haven't bothered to listen to the 6 seconds of recording they apparently left behind.

Five calls from this same number starting at 522am.   I don't understand what they can possibly hope to accomplish.

Received a call on my personal cell phone at approx. 1 AM August 21, 2013.  As I did not recognize the number, I did not answer.  No message left.

They called me at 3:00 AM.  Didn't say who they were; just said "We will remove you from our call list."