Unable to update new iPhone 4S: Error on SIM card

As I am trying to update my new iPhone 4S, I received an error stating that “Only compatible SIM cards from a supported carrier may be used to activate iPhone. Please insert the SIM card that came with your iPhone or visit a supported carrier's store to receive a replacement SIM card." I never used any sim cards or even take out my sim card on my phone. I brought my iPhone to the Apple Store near our place and my problem is questionable to them. So they just replaced it with something new. But the same thing happened after the replacement. What is causing this problem? Help please.
