Hi Folks, I purchased a factory unlocked 4s phone back in November and using it without issues until about a week ago when the backlight malfunctioned. Apple replaced the phone (mail-in-replacement) without issues. The replacement phone that was received however doesn't appear to be factory unlocked. Here's what happens: 1. The replacement iPhone came with an AT&T sim card pre-installed in it. My original factory unlocked phone did not. 2. I can activate the phone without any problem using the AT&T sim card provided, however, when I insert my foreign sim card, the apple logo splash screen comes up and states that activation is required. I tried activating through iTunes, through WiFi on the device, and using the cellular data connection and on all three occasions the device states that activation cannot occur because the sim card is not supported (or something to that extent). Did I actually get an AT&T locked phone as a replacement or did I mess up on the activation somehow? Thanks in advance!