So I bought a 5C and it arrived today, but I threw out the sim card that it came with thinking I could just pop in one that I got previously from the ATT store in it to do a cross upgrade. Now I am getting the error that it cannot activate and it is saying "The SIM in your iPhone is not the one that shipped with it. Please reinsert that SIM and restart the iPhone." I have no way of retrieving the SIM card and I went to the ATT and Apple store and they could not help me for 3 hours. Should I just exchange the 5C for the same 5C and restart the process?