See.. Your Phone comes with Region lock and it has warranty as per that region Only and Software Update has Three Binaries/Codes out of which CSC code is most important and then the PDA code and when you try for update through OTA it matches both and PDA & CSC...And if you purchased handset from other region and using it some other region then because of this Mismatch many users are not getting updates as per the using Area...So check if you are using your handset in same region where you purchased or at some other region.... Also check whether in your region this update is available or not I am going as per Indian Region only...
I think it belongs to Singapore !! Are you using it in Singapore ?? Or using in some other region ?? Also check Version 10 is updated in Singapore or not ??
Then Visit to your Authorised Service Centre and ask them how to get Updates as per Bangladesh region if you want then.....They will help you out more....
