i think my iphone 6 plus is hacked Help

Recently my iphone 6 plus has been doing some weird things. I get calls saying i called them but I have not and it doesn't even show in the call log. All the number from the calls start with "379" like my phone which is to much for coincidence. I even got numbers from foreign countries asking for different people but since i cant understand i hang up. This used to never happen about a month ago i got a txt from some random person on kik it looked like a video. Then my whole phone just went blue and then rebooted. If my phone is hacked can someone please tell me what to do it feels unsettling for my information to be floating about.😕😢😟