Called Sunday at 8:30pm EST. It is a Chicago based AT&T number. They left no message. I texted to ask who it was in the morning and received an automated reply: "Thanks for the message. Configure your phone number's SMS URL to change this message. Reply HELP for help. Reply STOP to unsubscribe. Msg&Data rates may apply." Naturally I replied "STOP" and received: "You have successfully been unsubscribed. You will not receive any more messages from this number." Hopefully that is the last of it.