I just got a call from this # I did not recognize the number so I ignored it. They left a voice mail so I check it and I hear a beep and nothing else. Like Jew Jitsu said they will call you around every 10 min.
623-444-3399 called my mobile phone at 3:41AM ten consecutive times, leaving ten blank voicemail messages. The last call was 4:08AM. Even if you have an auto fax, you should be smart enough to not have it sending anything past 9PM in any time zone.