My friend wanted to jailbreak my phone and she took it and jailbroke it then I told her I didn't want it so I restarted it and now my phone is stuck on the apple logo with a loading bar at the bottom. Is there a way I can fix it? Will apple fix it if I tell them?
You can restore your iPhone follow this instruction OR ask Apple do the restore for you.
Run iTunes on PC and make sure that you are using the latest iTunes.
Then connect your Device with computer via USB cable, and then Tab on summary option, see in the left side bar of iTunes
Now Select restore option from iTunes and then confirm the Restore Message for better results. After this unplug your Device and Restart it.