A few days ago I had a couple of calls where the phone didn't ring and if the people who called hadn't left voicemail , I would never have known about it . Calls were not listed in missed calls . Do Not Disturb is not on . Phone is not on silence or vibrate . Today it got worse , no call came through . Tested with a friend at the other end of the couch Resetting networks seemed to work for a while . When loading iOS 7 , I did a clean install and all went fine . I got the iMessage problem after installing 7.0.2 and now this . Has anyone else have this issue ?