I just figured that would help you find the file you were looking for. Look on the page in the link I posted and look for tour region (UK), and match the numbers of that firmware to the stock ROM you have on your computer. Make sure you have the correct android version (4.4.2 most likely). If you don't see the same numbers then maybe you don't have the stock firmware on your computer and will have to download it. It will be something like KBX20.9-10... If you locate the correct firmware, I may be able to further assist you.
Edit: I'm sorry , it should be something like 174.44.9 if it was 4.4.2 KitKat.