Wifi would be free, assuming you are using it in your home or at an open hotspot. It will still work even if data is disabled on your sim card. Wifi is based off the device itself.
make sure data is blocked and stuff cause u mite accidently connect to internet thru service provider.. I got scammed once cause I was told my Sim was data blocked.... And when u connect make sure it ask you to connect to a wifi connection
is a simple change, just delete the provider's address and phone number like options in your phone so that when you click into the internet icon or whatever, it can't connect to your ISP for the web browsing;
Connecting to wifi is always free.. being able to go online is a different story. ex. like connecting to starbucks wifi, the browser leads you to at&t site which you gotta pay >.>
Wifi costs depend on the provider you are connected to, if you connect to your home Wifi it will be free, if you are outside your home and connect to another access point it can either be free or they will charge. If they charge you will more than likely see a landing page, if its free you can surf but be careful it might not be safe so dont go doing online banking etc. The other access points you may not be able to access because they are protected. I have had a wifi phone now for a while and all the new phones nearly all have wifi, its a must on mobile phones now i use mine nearly all the time along with 3G when no wifi is around
LOL, you should call your service provider and ask how it works because we are replying from a different country and different service providers has different policy