On sunday my friend's 5C just turned off while she was texting someone and wouldn't turn back on. Usually I would dismiss it as her doing something wrong but I saw for myself that the phone just would not turn on no matter what I did. I plugged it into the charger and it vibrated but still didn't turn after an hour of being plugged in. I told her to take it to the genius bar. Yesterday I was at the genius bar and across from me was a woman that had the exact same issue with her 5C!