Fully agree with torontokids. You need to remain professional and not let emotions get involved. This is a business we run, and need to conduct ourselves. Moving forward, you respond by saying "thanks for inquiring, good luck". I would also suggest if you close at 6pm you tell them you close at 6 and leave out your late fees during this initial inquiry. That is something they will read in your handbook or can be said during interviews if asked.