different IMEI than the one written on the phone under the battery note 3 n9005

Hello,
I bought a note 3 n9005 european sim model

-from settings my phone reads different IMEI than the one written on the phone under the battery.

-The network goes down to emergency call only but never asked me for unlock PIN

-someone installed for me android 4.4.2 that deleted all options like air gestures and all other Samsung stuffs

- I wanted to return the phone to stock settings, firmware and unlock it.

-knox already tripped