Unprofessional

I was at McDonald’s Cavendish Square. I was standing in an empty store with many staff for about 3-5 minutes until someone approached me..... I asked why does it take so long for someone to assist me. The person who appears to be the supervisor abruptly says the queue is not where you standing. I decide to leave the store because the man was rude and how am I supposed to know where the queue is when someone takes so long to assist me in an empty store with many staff?