Apple issued a carrier settings update for iPhone 5 that work on the Verizon network to fix a problem where the iPhone may use cellular data while it is connected to a Wi-Fi network.
To update carrier settings follow these steps:
- Go to Settings > General > About
- Wait for the alert to appear
- Tap "OK" to install the update
- Hold the Sleep/Wake button down until you see "slide to power off"
- Slide to power off
- After the device powers off, hold the Sleep/Wake button to turn your phone back on