Quest problem?

I screwed up a quest and now I can't get it back.

This was for the 5.1 landfall daily quests, Hordeside. I got a quest which led me through a purple portal to Belloc Brightblade, which led me to the quest "Taking Advantage". This quest urges you to take another purple portal into some ruins. Handing it in unlocks a bunch more dailies, I hear.

I got the quest from Brightblade, then got bored and promptly wandered off and forgot about the whole thing for a few weeks.

I came back and, I assume I didn't read the quest again properly, because I fail. I had forgotten the second portal existed and tried to take the portal from Domination Point, but of course, it wasn't there. So I tried to go into the mines and got lost a lot and died a lot, gave up, rezzed at the GY, and rather than read the goddamn quest I decided to abandon it and take the quest again to see if it would make the portal appear.

Of course, it didn't, because I was looking for the wrong dang portal. And I was wondering why I couldn't take the quest again from Domination Point.

Looked it up on WoWhead (thank god I remembered the name), comprehension dawned: "Oooh, I DID hand that first quest, I have to take this one again from BRIGHTBLADE! And there's a portal next to HIM. RIGHT!"

... Except now Brightblade won't give me a quest. I swear to god it was "Taking Advantage" I abandoned, and according to WoWhead it is definitely Brightblade who offers the quest. It must be Taking Advantage I abandoned, because I can't get the prerequisite either. And it goes without saying I definitely did not hand in the quest and forgot about it; I distinctly remember that much.

I've probably missed something really obvious somewhere because I've already proven myself to be something of an idiot. Oops.

Help?

ETA: Thanks to everyone who answered! It was, indeed, the wrong day. But today I managed to pick it up again no problem. :)