Lv. 1 Wizard with Prestidigitation. Color the walls like, orange and neon green, or something horrible or excruciating to look at. Eventually,the guards will get sick of it and call someone to paint over it. Jack his clothes, tape his mouth or whatever, and leave!
Or, through using Message, get people to believe that you're a famous person of some type, and when a guard comes for an autograph, cast touch of fatigue on him. Offer to help him out of the pit. Once out, cast obscuring mist, and make your escape!