I got a call yesterday 2-24-2015, I answered but was silent. I tried to call back several times but always had a busy tone. Got a call again today 2-25-2015 . I had put it into contact list so I could identify this caller if I got another call. So I let it ring hoping for voice message. It did not leave one. I called back, got busy tone once again. I think it is a robot/ automated.