Loss of Crusader Title

Q u o t e:
So i did that faction change thing, and lost my crusader title. WTF Blizz

Unfortunately, you will need to reacquire this title by working your way up the ranks again. We have also made several posts related to this subject, as well as it being stated in the FAQ about the Character Faction Change Service.

Please note that the following line is stated several times throughout the FAQ. " **Please note that all achievements relating to the Argent Tournament will be reset.** "

http://us.blizzard.com/support/article.xml?locale=en_US&tag=FCFAQ