"Appointment mix-up"

My 81 year old Father-in-law was due to have a colonoscopy. He received his appointment and then got all his bowel preparation through the post. He followed the dietary advice for the 3 days leading up to his appointment and then took all the bowel prep as advised. When he arrived at the hospital on the day of his appointment, he was told that there was a mistake and he did not have an appointment for the colonoscopy on this day, but to go away and await details of a future appointment date.