Is the one player you mention the only one giving you grief, or is he just the leader or most successful? It sounds like more than just one of your players are chafing under your restrictions.
Quote Originally Posted by Discipol View Post
I don't want them to leave the dungeon until the task is complete, and to stop them from free-walking in the dungeon, where as I want them to have a linear path, at least for a while.
It sounds like you want a style of game that doesn't interest your players. You might want to a) save that game for a different group and run something your current players will enjoy instead, b) talk to them and see if they can cut you some slack in this regard and scratch their itch later in the game or in the next / a parallel campaign.