demand a stop to unfair reprimands in the workplace

I was demoted after having a Supervisor position for 21 years. My supervisor now has been there 3-5 years. The first or second years of her being my Supervisor she suspended me for not going to clean up a infested house with bed bugs, I have no training in that area. This time she said she came to the home where I work and the house was filthy. 21 years I supervised 5 houses and staff never got a complaint from my supervisor and never failed and inspection of any kind. All of my evaluations are excellent until until she came.