You realize installing a patch is a rather complicated process, and requires them to take the servers down to do it? It makes sense that they don't want to do this on the weekend when a lot of people are playing. Besides, how do you KNOW that they have the patch ready?
Do you seriously think they have everything ready to go and are delaying it just to spite you?
The key here OP is that it is not one quest, there are many quests bugged for people , i found none myself , but im sure people are not lying about the problem.
So it is not one small quick fix , it is one big fix.
"Never attribute to malice that which is adequately explained by stupidity."
-Hanlon's razor
Which makes it even worse with so many bugged quests. They like refuse to give any support on bugged quests and just say that they are investigation it. Maybe you should have investigated it during the beta.