You may wish to contact the company to find out more about why your application was not successful. Employers may have valid reasons for choosing one candidate over another, such as the person’s qualifications, experience, interpersonal skills, and other job-related qualities. What is important is that the hiring process is fair and that applicants are considered fairly based on merit.
You should lodge a complaint only if you have reason to believe that the employer has not been fair in its hiring process. You can report them to the Tripartite Alliance for Fair and Progressive Employment Practices (TAFEP).