I bought a Iphone3g running 3.0 from my friend.i bought it for cheap and it is better than my phone so i was just wanting to use it for basic calls, and sms on tmobile network. I do not have an internet plan but i have ulimited calling/text. I tried jailbreaking this phone and it worked. but then i inserted my tmobile sim into the phone and it shows dots where the towers should be up in the corner and no network. can i used this the way i want it? if you know anything please comment. thank you.