Not like I didn't believe you guys but you were right. Its been confirmed by support, I'd gain one.
Thank you for contacting TERA Support Team.
You have 8 character slots with a veteran account. In your case since you have already 7 character slots you will only have one more.
Don't hesitate to contact us again if you have any further questions.
With best regards,
Feel free to lock the thread. I got what I came for
Thanks again to all!