grievance
noun
uk/ˈɡriːvəns/ us [ C or U ]
a complaint or a strong feeling that you have been treated unfairly:
have/nurse a grievance against sb He has been nursing a grievance against the company for several years.
[ C ] HR
an official complaint by an employee that they have been treated unfairly:
file/raise a grievance An employee may file a grievance against a manager in accordance with the provisions set forth in their contract.
The aim of a grievance procedure is to encourage fairness in the handling of workplace problems.