Nokia 9300 is locked

Hi,
i just buy nokia 9300 and its locked, if i change my sim card and try to call it says "beeb beeb beeb" and i cant send sms, but sometimes my phone can send sms, i unlocket it by cable but still nothink. One man told me thats my IMEi is locked to operator and it cant be unlocked, its true? he told me if i change my IMEi every thing will work fine, so maybe there is another way to unlock this phone? ( sorry for my english )

thanks for replies

[kiran1]

There is a way to unlock your mobile..It can be unlocked using the code ..I found the site http://www.superunlockcodes.com/nokia-9300/rs12wp9/ .Here i found the valid unlocking codes for your Nokia..Through this you can unlock your mobile easily..