Good day

If you are an educator in the private sector; you should refer to your employment contract. The employment contract should set out what is required from you by your employer. The employment contract will also have the companies policy attached to it, most employers state that some times the employer will expect more from the employee. The employer could have sent an email or letter conveying his/her instruction to all employees that this might take place. This instruction is a direct order and should be followed else you face insubordination. If you feel that none of the above mentioned applies to you in your matter, it is suggested you draft a formal grievance letter to your employer to start the appeal process. 

If you are in the public sector; you will have to revert to your appointment letter. It is suggested you familiarize yourself with the function and responsibilities your position holds. This depends on your pay level and can be requested from the department directly. The orders must come from an person who has been issued with the correct authority to make such a decision. If this is not the case then it is suggested that you lay a grievance with your superior as well as the HOD to explain your position. 

Regards 

LP