So a few days ago I joined 5 men group doing wpvp in Azure Span farming blood tokens, 2 heals in the group, I stayed near the edge to farm without getting focus fired, and keep myself alive, spent about an hour fighting like crazy, near the end of the fest, I got this quest popped up, I didn’t know what it’s but clicked accept in the middle of this big fight, then there’s a kill count showed up, quickly got to 10 and disappeared, after about a few more minutes I was killed and group disbanded.
I flew out and saw the big finish quest banner on right just like other completed WQ, I ported to Valdrakken thinking to look at the quest to see what it’s first. Clicked on the banner it says “the horde slayer” quest, with “complete quest” button at the bottom, so I clicked the button but nothing happened, so I clicked multiple times, nothing… I though maybe I need to go back to the zone? so I flew back with the quest window open, but quickly the window disappeared! I lost the quest and didn’t get the title!
I opened a ticket and got the answer today, the GM said after investigations, he found out the quest “the horde slayer” was abandoned, that’s why I didn’t get the title. Excuse me, why in the world would I abandon this quest? The quest is lost without trace due to whatever bug blizzard has. To be honest this is really bad experience, this is obviously blizzard’s bug, not mine. I have earned “the horde slayer” title.
Followed up with the ticket but am not hopeful this will be done right and title given, this title is very situational and almost impossible to duplicate, otherwise I won’t bother just re-do it 
Anyway, thanks for reading and happy thanksgiving…
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I got the new GM reply today, confirmed that I got the quest, and completed it, here is the quote:
“I can verify in the logs you did indeed get the quest, kill the required amount, and then left the zone as you stated and then the quest was abandoned. So this all lines up perfectly with what you originally said. This is not something we would help fix since that is how it is supposed to work. In the future, don’t leave the zone until after you complete the quest.”
the thing is, this is pvp quest, it’s not a world quest that’s given/completed in a fixed zone, I can do it anywhere. currently WQ will even auto-complete after I finish the task, which is how it should be, task completed, give the credit what’s the problem? the technicality that I have to click complete in the same place otherwise will be abandoned by system is just absurd. actually the system never shall/will abandon completed quest of any kind without player action as far as I know. I replied to the ticket and hope for the best… happy thanksgiving!