How to turn OFF T-Mobile data service for Internet on 3GS?


Feb 6, 2012
I'm a new iPhone user, and I've gotten my unlocked 3GS to work on T-Mobile's "Pay as You Go" system, where I buy a $100 block of minutes and use them up gradually, then buy another block etc. I don't use the phone much, so this is better for me than a $49/month plan or whatever.

I do plan on using the iPhone for internet access, emails etc., but I don't want to burn up too many of those minutes, since I'm a cheap SOB. I hope to mostly (maybe entirely) use it on WiFi since my house has its own WiFi network. I've already used this phone on it (before I put in the SIM card), and it works well.

Is there a way I can get the 3GS to tell me "Sorry, I can't connect to the Internet" or something like that, when I tap on "Weather" or something requiring internet, and it's in an area where it's receiving T-Mobile signals but NOT receiving WiFi?

Once I get that message, then I can decide if I want to spend some minutes by manually allowing it to connect to T-Mobile's data service this time.

What I'm trying to avoid, is using minutes when I don't know about it, when I tap Weather and the 3GS finds there's no WiFi, so it quietly connects to T-Mobile's data service without telling me.

Can it be done?