I have data Right now because After a while, Att will just still send a SMS message to tell me that I am using an iPhone and requie to use data plan. They will add it without my concent.
Yes. They will ban your iPhone from connecting to their network(8 of friends got banned in Los Angeles area)at&t will send you an SMS first, and ban your iPhone after 2 billing cycle if you ignore att(usually 1-2 csr will call you in between) after that,you can still use your current voice plan on other phone but not that iPhone.