mobile

My phone has never been rooted and is stuck at 4.4.2. I've tried dozens of times to update using OTA or Kies with no luck. It keeps saying "Software Update Interrupted. Your software is up to date." Fatory reset doesn't help either.

I tried going to Best Buy to have them update it, but the one guy helping wasn't really helping. After 20 minutes of waiting on him, he pretty much gave me a bull**** run around and told me to get back there some other time.

I haven't been messing around with android much lately and not sure about all the details of how roms or updates are installed. Can someone please briefly explain if I need to be on 4.4.4 to get to 5.0 and what steps I need to take? I don't need root and don't want any mods.

Thanks!