i got it,
4) Firmware update not available for you Firmware update 20.0.012 is released for most generic product codes for now and not for all product codes. It will be available for all product codes gradually. You can find your product code on your phone below the battery. Check the list James provided below in the comments, if your product code is not in the list, you have to wait for sometime till the firmware is released for your product code.
If you are too desperate to update your phone and cant wait for sometime, you can try changing the product code to any of the code James mentioned below by using any of the tools like JAF, Nemesis or Phoenix. Google it for more info on how to change product code of mobile. We can write a step-by-step tutorial for that if you need.
We advise all of you to not change the product codes and have patience till the update is released for worldwide users for all product codes. Nokia is evaluating the responses and issues people are having with this update, a minor update again is possible in next few days with all of these issues fixed.
Nokia has launched a revolutionary product with completely new platform and OS, so issues like these are likely to come up during the launch. Nokia has always delivered what it promises, so lets be with them and have some patience till everything stabilizes for Nokia 5800. Cheers!!
UPDATE 3 (Mar 30)
Though this firmware update is available for about 2 months now, Nokia officially announced about it today. Official update from Nokia means it should be available now at all parts of the world. The update may still not be available directly on your mobile (via OTA) but should be available now via Nokia Software Updater utility.
“The update includes great improvements in the Nokia 5800 XpressMusic. As mobile devices become more and more advanced, additional features and new functionalities are easy to install to the existing device. We recommend people to take advantage of the new features and upgrade their Nokia 5800 XpressMusic, and get more from their existing device,” said Soren Petersen, Senior Vice President, Devices, Nokia.
Check the official Press Release