Nokia N93i cannot upgrade to another firmware!!!

I bought a Nokia n93i a month ago. After 2 weeks, it just froze up, so I took it to a repair centre to see what they could do, but they couldn't do anything so they sent it to Nokia.

3 weeks without a phone, I find out that Nokia couldn't repair it and so they send me a replacement. I go and collect it and it seems to be working fine, but then I notice the firmware is now: V10.0.025 which was much lower than my previous model. So I attempt to upgrade it and now I get this message:

"The phone model is currently not supported"

Suffice to say, I am now getting rather annoyed as I know that this old firmware has a few bugs. Does anyone have an idea on how to get the latest firmware by any other means than going through the software updater? Or does anyone know of a way to change my product code as that is what that stupid Nokia Updater is saying is not supported. My product code is: 0544181
I would be most grateful for an answer.