They called and left no message. I blocked my phone number and called them back. Got a message that said "thank you for calling. . . (Something about "special promotions") . . If you would like to be placed on our do not call list press 1." So it would be safe to assume that this is a telemarketer making random calls since, like all cell numbers, my phone number is unlisted and I have not given it out to anyone but friends and essential services like the MD office.