Can't do the succubus quest (Horde, undead)

Hi, I was trying to do the succubus quest, I got the first one of the chain that starts in silvermoon and sends you to Carendin Halgar in undercity, I submitted that quest, and that same NPC was supposed to give me the next one of the chain, but he didn't. Now I can't continue, and I can't abandon the first quest because I submitted it already. It's been 3 days, I've put a ticket in game and hasn't received an answer in all these days. Any ideas?


e: I've done the Felhound one with no problems.