@jenn77lee, i truly hope your time in Mexico is going well. I'm sure the weather is much more enjoyable than where I'm currently sitting. Let's ensure you don't endure any roaming charges on your next bill. An extended coverage area is a specific type of roaming. In an extended coverage you are tied to a non-Verizon Wireless tower. This typically happens within the United States. While in Mexico, do you have data turned off or did you add an international data package to suite your needs? To ensure that data is turned off an not accumulating roaming charges head into Settings > General > Cellular > Roaming > Data (off). You can keep Roaming voice only on to ensure you are able to call.
Follow us on Twitter @VZWsupport