Why can't I turn off Airplane mode?

[Windows Central Question]

I recently started using a different Lumia 620 (my previous one had issues with the power button) and when the phone turns on the airplane logo will appear on that status bar. When I turn it off, the phone will not read my SIM card (works on other mobiles) and the phone begins to overheat and restart. I've tried to do hard restarts, I've even attempted to update the phone to WP10 but for some reason it won't do it.
The problem has been with the phone from WP8.0.1 and updating to 8.1 or 10 did not fix the issue.

Phone is Lumia 620
OS 10.0.10536.1004
firmware 3058.50000.1425.0001
hardware 5.0.2.5