Is there a way I can switch to WiFi only and use basic phone functions such as calls and texting? I don't want to keep paying for the expensive data plan and want to use it for phone functions and WiFi only. Is this possible?

i'm in the same boat. i wanna do mms and do not want to use the internet for anything else unless i am on wifi.... i have turned internet completly off on my phones because of the charges... i would love to turn on pay per use because mms is covered under my unlimited messaging option... i just need to make sure me and my wife never use any other internet function or disable all other internet functions unless under wifi.. any help would be greatly appreciated.