Hi, aua123.
You can unlock your Samsung Galaxy SIII phone from network lock using unlock code.Unlock code is the best way to unlock phone.You can get unlock code for your phone from Unlock Zone - Unlocking the Samsung Galaxy S III mobile phone here you need to specify your Network name to which it is locked,IMEI number of your phone.Then they deliver unlock code to you through mail with unlocking instructions.By using this you can unlock your mobile easily.