@Arifrefai If you have issues with your code, though, that may mean you already installed the game on a PC, and because of that, it needs to be unlinked from that PC before you can use it again. It's a system preventing the game from being used by multiple people. It's a rather dumb system though, since a fatal PC crash will obviously make this impossible.
For key-related issues like this you should probably contact EA tech support through help.ea.com. They can actually look into your account details to solve such things. Just click on and fill in information until you end up on the live chat with the tech support people.