Ok, so I REALLY want my '"Master of the Oasis" badge, but I can't get it! Why? Because I lost my quest for Tomb of the Beguiler! I can't even get it back because the mander guy that gives you the quest, does't even have the grey "?" over his head! And he doesn't have the yellow "!" either! Not only I don't get my "Master of the Oasis" badge, but I also don't get my "Tomb Raider" badge! I can still go in the dungeon though.
If Jah'Mes still is blank outside of the Tomb, go inside and see if he has anything for you to do in there. If not, you may need to send in a ticket to Support.