Did you put the code with the sim card inserted? What error message does it give you? How many times prior to me giving you the code haveyou tried to unlock the phone?
If you get this error it means that your phone is HARDLOCKED. NO one can remotely unlock your phone. You will have to send it in to get it unlocked. You can check out www.iunlock.com for service in the USA. If you want UK service, PM me and I will give you the emailID of a trusted source. Sorry.