Are you sure you are at the level 1 dungeon? In later acts it is possible find a higher level dungeons first, though in act one the placement is pretty straightforward, with the level 1, 2 and 3 dungeons are over the first, second and third bridges, respectively.
Do you have a save before you first entered the BF that you can revert to, at least temporarily? The BF is generated the first time you enter in each act, so if there is a problem with the BF itself, perhaps entering again from an earlier save will bypass that.
Did you find the first level 1 BF key in act 1? If so, you don't have much to replay if you do end up needing to start over. There is a partly hidden chest in the starting cell block...
on the southern path, near where you would have fought the south west guard if you approached from the south east, there is a locked chest partly obscured by chains and a steam vent, containing the first of 2 level 1 BF keys for act 1, with the key for it hidden in the left cell in the arena.