Security Key login problem
What you can do is first verify you have the correct Display Name and password. To do this go to swtor.com and click on login and then click "Forgot your Display Name" below the first field, enter the email associated with your account to get your Display Name via email.
If you know it's correct or have verified, use the "Forgot your Password" field to send a recovery email to reset your password. Once your password is reset, you can then go back to the website, login with just your Display Name and Password but leave the security key field blank then click login.
It should ask for your Security Key and if it does below the field is a "Lost your security key" link that you can click on to receive an email to remove it. Once removed you can then setup a new one on your current phone using the security key app.
If you need screen shots on setting up your Security Key you can find that located here.
If you cannot reset your password or remove your security key, you will need to call Customer Service for further assistance. Their contact info and hours of operation are found here. You can also use a VoIP programe like Skype or Whatsapp to call Customer service for free or at a discounted rate using the internet.
