Walmart Overnight Stocker interview questions

The interview went very well. I already knew what they are going to ask and I gave them the exact answers they were expecting. The interviewer told me that, I answered every questions correctly, but the position I interviewed for is already filled. I don't understand why she interviewed me for a position that doesn't exit anymore.

The questions was quite average as far as why would you like to work at Walmart, how would you rate yourself as a worker from one to ten and ten being the highest?..Are you a team player and if so describe how? Then there was a scenario given and you answer how you would deal with it.Overall the interview was very well organized