I have submitted a ticket Question Reference # 200402-002422 a few day ago concerning the main quest. You see, I got into a dungeon while doing the main quest, I was in the wailing prison. The problem is, I cannot get back there in any shape way or form. I also can't abandon the main quest because abandoning the main quest is impossible. The answer I got from zos is: Greetings!
If you are having trouble finding your quest NPC, first make sure you’re in the right location in Tamriel. Quest NPCs can move to new locations in the game based on your personal quest progression. If you’re certain that you are in the right location and still don’t see the quest NPC you are looking for, try the following:
Log completely out of the game for at least 15 minutes. This performs a soft reset and loads your character into a new game instance, refreshing your surroundings, which prompts the missing, invisible, stuck, or un-interactable NPC to act as intended.
On PC/Mac, you can also try using /reloadui to reset the environment or /stuck which may get you past an objective.
If all else fails, abandon the quest and re-start it. This should allow the environment to reset and allow the game to respawn the missing NPC.
Very frustrating because I have explained my issue the same way I have done in this post, and yet someone at their customer support sent a template back to me without even reading my issue.