Did you include (uncredited) in the attribute box in your submission?
US commercial-supported broadcast network (FTA) primetime episodic shows are notorious for having very limited onscreen credits. Usually only heads of department, and a limited number of cast get listed. This isn't a reflection of the quantity or quality of work done on a project, merely a numbers game. Theatrical films and premium TV are less restrictive. They're not as focused on limiting the credits to leave room for commercials/coming attractions as the broadcast networks.
Looking at recent episodes of "The Vampire Diaries", 15 to 20 cast credits seems to be the current mode for this series. Your callsheet lists you at #65 on the cast list which pretty much guarantees you did not/will not receive onscreen credit. So the (uncredited) attribute is mandatory if you want this credit to remain on the page.
Should, by some miracle, your name appear in those onscreen credits when this episode airs, screencap those credits and submit to have (uncredited) removed. But again, that scenario is remote.