Trying to turn roaming off- "Network" nowhere to be found in settings??!

I can't be the only one tripping out over this...

In Mexico, would love to turn my VOICE roaming off. Have turned data off.

I want my cell phone reduced to a iPod's capabilities for the next week- only wifi.

iPhone: Tap Settings > General > Network

That should be where I go to turn this off, yet Network isn't an option under my General settings, or anywhere on my phone???!

Freaking. Out. Please help! 🙂