I bought the Pack of the Fallen in the Zen store that gave "The Fallen" title and Horns. The Eyes of the Fallen were added to the claim vendor as verified by this forum post:
https://www.arcgames.com/en/forums/neverwinter#/discussion/1254929I never removed the Eyes of the Fallen from my claim vendor, but now they are gone. I noticed they were missing after I purchased the Charity Pack Groupees and claimed my item.
I contacted in game help (ticket# 187554) and was told a GM can not help and it will be elevated to the Developers with a recommendation to make a post on the Bug Reports Forum.