"Anything else?The computer came ..."

Anything else? The computer came up with a list of available appointment times. I tried to book the first available time quoted,only to be told the appointment was not available.This procedure was followed a further twelve times, when halfway through the list a message came up to say that no appointments were available and to select another clinic. If no appointments are available, why are they on the list? What is the point of having a system that does not work, there seems little point in just wasting peoples time and effort.