I recieved a message on my iPad that someone was making a Face Time call from (my device's name) iPhone. My iPhone was not being used for a call. I woke my phone and the lock screen was different and my icons had been rearranged. I went to Find My iPhone and there was another iPhone with my iPhone's name that was offline. For the past 2 days, I have noticed reduced battery usage also. Has my phone been hacked? What do I do now? Please help!