We've checked the coverage of the area and, fortunately, there are no outages over there. Have you tried resetting the device?
Please, follow these steps to program your phone:
1. Turn Wi-Fi off and Mobile Data on
- Settings > Wi-Fi > Off
- Settings > Data Usage > Mobile Data > On
2. Check signal strength (3 bars, or 60% is recommended)
3. From the dial pad enter ##72786# (press "ok" when prompted. For HTC devices, press MENU>RESET)
4. The cellphone is going to update the Profile and the PRL and reboot automatically. That should take about 3 minutes.