Good luck. But it would be very hard to prove. Is there anything in your contract that gives them freedom to reassign you? We literally have something in our contract that says very vague that administration reserves their rights to change your assignment to benefit the district. You can argue against it but only up to the point. They acknowledge your concern but then will do what suits them.

My daughter actually left a job that wasn’t what they described to her. She had two jobs offers and she went with the one that offered more money and job description matching what she wanted but when she started it was mostly not what she was told. She was bored out of her mind. Her job field is a combination of couple of things and depending on the set up, it could be more one thing over the other. When she asked them, they said her tasks will vary so eventually it would be more of what she wanted. But she didn’t want to sit and wait. She left that job in a few months but she found a new job first.