How do I report a GM?

So yesterday I had possibly the worst GM ever in this game. How does one go about reporting a GM?

Here's some background:

We were raiding Gruul's Lair. After we down High King, we had to swap out a few members of the raid. A few people that were in the raid for HK ported out and left raid, and a few people that weren't in the raid joined the raid and zoned in. Normally, as soon as the new people zone in, they are saved to the instance. That did not happen in this case (they entered a new instance).

One of our members that was in the raid when we down HK then decided to go out and reenter the instance. We he reentered the instance, he found that he was not saved to it either. In fact, upon checking we found that about half the people that were still inside the instance, standing next to HK's corpse, were not saved to the instance.

We tried several times to reform the raid, etc..., but still only about 10 of us were saved, and we could not get anyone else saved to the instance.

So, here's the gist of the conversation I had with <GM>[Removed] (I didn't save the whole log, but I do have a couple screen shots):

Me: (describe the problem)
GM: One of your players must have done something wrong. Have you checked the forums on this issue?
Me: That is not possible, we have done Gruul's lair many times.
Me: No, I have not checked the forums on this issue.
GM: I bet you have not read the patch notes either.
Me: Yes, I have read the patch notes.
GM: Just that. Like I said, one or more of your members has done something this instance does not want you to do. To find out what it is, go to the forums. Is there anything else I can help you with?
Me: Which forum should I go to?
GM: Since there is not another issue, I must take my leave to assist other players.
(ticket closed).


WTF?