SPV C550 firmware/screen problem?

[Guest McGills]

last night i was using my c550 as usual, working perfect, but when i woke up this morning the screen was not working, it would come up as a blank white screen, even after restarting etc. but every once in a while the screen would flicker with all different colours. i went to a phone shop today and they told me that its more likely the firmware needed upgrading, can anyone help me find what im looking for because ive never done this before. cheers