For Mental Harassment

My wife working is a private international school as a PRT teacher post last 3.5 yrs. She is doing to D.ED from BHOJ Private University. 2019 is the last year of D.Ed. final years exam date is 07 Jan 2019 to 25 Jan 2019. All the casual leave is use to this exam. but school principal said to my wife " madam i will sanction your leave and your CL balance is zero after that i will not give you any type of leave and you will need the leave it should be consider of LWP". one day my wife health condition is not good and she inform the principal over the phone and ask to the Medical leave but principal not sanction leave and told to my wife give you resignation letter if you are not come to school because tomorrow is a PTM so you will come to school. but my wife is not going to school due to health condition and she inform to Principal over the TEXT Massage. After that i think Principal is take a strong action against to my wife and he is doing to mentally harassment of my wife . so please suggest my right way to deal with all condition. Email ID - [deleted]