If the key has already been activated unfortunately we are not able to provide you with a refund.
Please note that as Kinguin, we sell products in the form of keys, gifts or accounts and not the games directly. Our responsibility is to ensure that the key works to add the correct game to the platform it was meant for. If the key or gift has been successfully activated and the game has been added to the account, we cannot consider the product as faulty and therefore, we are unable to issue a refund.
Additionally, we do not have the power to make a key or gift active again and we cannot take the game away from the account the key was used on. This means that even if we wanted to, we are unable to accept a return and issue a refund on such a basis. We hope this clarifies the situation for you.