Raid Finder and Need Plus are both very new systems, and we’re working to iterate on these systems rapidly to ensure that everyone has the best possible experience as we learn more about how players are using the system. Please keep in mind that this system is not considered complete and we have further plans to improve upon it within Mists of Pandaria.
If you looted an item from Looking for Raid which replaced another and you need Game Master assistance to recover your old item, please place a petition with the new item name, that you can no longer use it - and the old item name you need restored. For more information on the affected items, please visit the Customer Support forums here- http://us.battle.net/wow/en/forum/topic/3729953854#1
We apologize for the inconvenience.