If you linked your account to any of the available methods, you should be able to log in using the same method. To log in to your account, you will need to go to the title screen (before entering the game) and select "Transfer Account" from the MENU tab on the top left.
Without an account link, it is not possible to restore an account.
Having a linked account is of utmost importance to ensure continued access to your profile in case of any issues with your current device.
If it is possible the account is linked to a different account, please be sure to try any of those possibilities.
In case you need any further assistance, please contact us.