I have a Samsung Galaxy core prime(Model number SM-G360F) and is unlocked and has Android 4.4.4 on it which is Kitkat and my son has the same phone locked to O2 and he had the upgrade to Lollipop months ago.

i keep checking for updates on my phone but still no update to Lollipop and i have connected mobile to Kies3 on laptop and i cant see anywhere on there to get the update.

So can anyone help in why my unlocked mobile has not got the update yet?

it was bought unlocked from day 1 from Carphone warehouse.

Same here I use it as a back up phone and I'm having the same problem as you .

I can't tell you why it hasn't been updated but I can point tou in the direction of haw to update.

Download the latest version of Odin (look on XDA website for this) and then download the firmware you want to flash (Sammobile have the firmwares). Looking at Sammobile the most upto date UK Open firmware is still on 4.4.4, if you want 5.0.2 you will either have to flash VF UK or you could flash a open Fance or Portugal firmware.

If you get the French one does it have a option for English ?