Worley Project Accountant interview questions

The interviewer seemed quite low down and was talking informally to me as a peer. She spent the hour attempting to dissuade me from applying as there would be too many administrative work. Final result: rejected as overqualified. I don't understand why I had to attend to the interview if they already had this conclusion in their mind. I also don't understand why they were recruiting a qualified accountant, at a qualified rate for an administrative position.