All new Samsung phones from T-Mobile and MetroPCS USA, comes with Device Unlock app installed. These phones can not be unlocked by an unlock code. We can still provide the code, but it will be useless for you. There will be no refund provided in such case.
There are various services to provide the factory unlock code for all types of Samsung devices. Some are limited to a specific country and some are worldwide, while a few services are continent based.
You may get only NCK code if in the database only has one set code of code.
Before placing an order check the device is asking for unlock code.