I was given a quest to kill the bandit leader at Snowpoint, but I already killed them all and they haven't respawned. I went back to the guy who gave me the quest, but he's still waiting for me to do the job.

Help?

Edit: by the way, I'm playing on Xbox.

Try waiting thirty days on the other side of the map then go back and see if the dungeon respawned

Errr, that would take forever, I can only wait 24 hours at a shot.

I wouldn't bother waiting. Maybe make a note on what day you got the quest, then every few days check the tower. Plenty of other things to see and do! I seem to recall a similar situation, which I think is connected to a http://www.uesp.net/wiki/Skyrim:Cragslane_Cavern. You'll be sent to a bandit cave to wipe the place out, but if you already cleared it you can't complete the quest. It takes several game days for respawns, and it might not be complete. Apparently that quest requires a certain number of kills at that location. Most "kill the bandit leader at x, y" quests that I've gotten spawn a leader even in a place I've cleared.

If he goes back to the cell it resets the timer AFAIK. So he would need to avoid the place for thirty in game days.

What a pain. It took me days to clear out all those stupid misc. quests.

You can pass the time by fast travelling from Riften to Markarth.

Leave your computer on overnight. Skyrim time is 8x real time. Get out of the cell first qnd just wait.