Number called twice a few days ago, at 9:00AM and 12:00PM exactly, then called again today.  They do not leave a message.  I called them back today and it is a recording, staying "If you would like to be removed from... (something about continued education)."  My advice would be to NOT pick up the phone, and call the number back and Press 1 right away, and you will be prompted to enter your 10-digit phone number to be removed from their calling list.  I am assuming they follow through.