i have exactly the same problem
i have exactly the same problem. i bought my phone at US from Google play.
the phone worked fine for two month and then i got - No Service, and its swipe in a sec to emergency call only.
i try to replaced some sim cards, and factory reset with no success.
i also read a bug report that opened in Google : 58317
they told that there is a problem with the radio interface and radio driver at the 4.3 update, and they will fix it in 4.4 kitkat version.
i hope that 4.4 will fix this terrible problem, if not the phone is totally a door blocker..