I have the Exalted Argent Champion of the Alliance achievement, which should grant the Crusader title and unlock the Crusader dailies and quartermaster. I was not awarded the Crusader title, I can’t do the Crusader dailies, and the quartermaster is still being a snob to me.
I unlocked the title on May 1, so it happened after the Cataclysm pre-patch dropped. I think there may be a bug preventing me from getting my Crusader title and access to the Crusader Quartermaster.
I also had this happen and same thing got it on May 1
Also has happened to me, I had the achievement on my main prior to the prepatch then decided to finish it off on my alt and I was not granted the achievement so I can’t do any of the quests.
Interestingly enough the Crusader title was given to me after the titles were fixed, but the quests and vendor are still locked.
Same thing happened to me on the 1st of May after the pre-patch when I completed the Exalted Argent Champion of the Alliance achievement.
The title randomly showed up over the last couple of days but the additional dailies and, more importantly, the Crusader’s Quartermaster are still not available to me.
We’re all three in the same boat now. I have the title but still no access to the quartermaster.
I know the good folk at Blizz are busy now, but I hope they can fix this for us.
Any update to this? I’m stuck in the same situation, the reply from blizzard for my first ticket was very generic as expected. Hoping someone had more success than me?
Same here, talked with Biz they said make a bug report 
I have re opened my ticket 3 times and the 3 times they did not understand the issue and only told me that i was eligible for the achievement and i was awarded it, still no access to crusader dailies or vendor
I have also earned the achievements but am unable to access the quartermaster in the tournament grounds. Hope this gets fixed as I have been grinding this out to get the mount.
still no word bumping
I checked at 10:00 pm ST. The Quartermaster is open for me!