Costume booking misunderstandings

It seems that there are always one or two people that do not seem to understand that when there is already a booking for a specific costume by someone else, that the costume will not miraculously be available for them or duplicate itself. Then they do not like to hear that a costume is not available and are determined to say that it is. When they still do not like the fact that the costume has been booked by someone else weeks or even months before the time, then they get angry. My website clearly shows which costume has bookings for when and includes collection and return dates. There is not way it can be made even simpler. If some people cannot use common sense, I cannot really help them.