Proper way to report character/account issues?

[expat]

I have the same issue on three characters (two migrated characters and one that I "bought" at the store just to see if I would have the same issue on him). What is the proper way to report the issue and get help? It doesn't seem to be a quest bug because when I use the .info "questname", it doesn't seem that it is a bugged quest. But it's a critical quest and none of my three characters can get past it. I've submitted GM tickets through the game but I think I am just pissing off the GMs - the last reply says "Stop submitting the same issue from multiple characters."

I don't want to piss the GMs off but I do want to progress in the game. What's the best way to get help and not get banned?

BACKGROUND: The quest is called "Keep your friends close"
https://www.wow-freakz.com/quest_helper.php?quest=40605&&name=keep-your-friends-close
This is the next to last step quest that opens up Broken Isles through Dalaran.

I completed the previous quest: "Demons Among Us" but the quest giver for the next quest (Lady Sylvanas Windrunner) doesn't give me the next quest. I can screenshot my character standing next to the quest giver and post it here if that will help.

Just please let me know what the acceptable method is to get help.

thanks.