I'm in the UK, and ordered my 6S from the Apple Store UK site on 12th Sep. It arrived as planned on 25th, and all was well. That night it crashed and rebooted with a weird pattern on the screen, and did the same yesterday morning. I took it to the Apple Store in Glasgow who said it was probably a hardware fault, so they gave me a new handset. However on this new handset, when I set it up, at activation it says "Device is activated on CDMA US network. International roaming requires a SIM." If I just press OK all seems well. I've had the same SIM/contract in a 5S, 6 and the original faulty 6S and never had this message before. Any ideas?