Compass Contract Group interview questions

I responded to an add in the newpaper. About a week after I sent in my resume, I received an email from agency to set up an interview. I was interviewed by one person, the Site Manager that was assigned to the location I applied for. The Site Manager had a copy of my resume in front of him and asked me my perspective about customer service. He told me about the company, some history and their vision, mission and goals. Then he asked how I handled certain situations in the past, i.e., rude customer, demanding customer, needy customer, terrorizing customer. He asked me to tell him about an experience/situation that I had to involve my supervisor. He asked what were my strengths and weaknesses. He said he had interviewed other candidates that were also qualified for the job, why should I hire you?