I bought iphone 4 , jailbreak it ,and installed ATT go phone prepaid sim card on it with 200mb data plan.Everything is working fine but 3g internet! I came to the att office they told me that att trying permantly block 3g data internet on pre-paid plans iphone.So i have to install APN setting or something like this after.Im trying to install it from cydia but nothing changed.Asking for help if anybody know how to solve it.Iphone 4 without internet it pretty much the same like brick wich can make call.