Not sure what there email address is

Just wanna no how is it possible for a manager to appoint a so called intern for a post wish is not available yet an a lower rank staff need to train her for her job wish in other words she's working more then four years for the company she already no from assistant,reception an computer literate ,the manager brought the intern from Kuruman why can't she apply for that up coming post ,it's just unfair for someone else to apply for that up coming post please assist .