"cancelled appointment"

My husband finally got an appointment for the referal from the Paula Carr eye clinic for his diabetic retinothapy after a 3 month wait. The appointment was booked for the 14th of September and i swapped a day at my work so i was able to accompany him for this appointment. We are really frustated that the appointment was cancelled with less than 24 hours notice, causing much inconvenience to both of us and leaving my husband again waiting for another appointment that was urgently requested in the first place. May i suggest at least 24 hours from yourselves is requested in the event of cancelled appointments so that other parties do not have to be put out.