"Good treatment but abismal timemanagent"

My mother was treated today as an out patient and as such had an appointment time of 12:30 we duly arrived on time after making the 47 mile drive. She was first seen on time and after a short wait she left us at 13:30. We were told that her op would be 90 minutes and they would call us to collect her when complete. As the time had reached 16:00 and we had no news my wife went to the collection point to check for an update. My mothers op had not started until 15:30! Why had no one told us there would be such a delay. Why did the nurse who spoke to my wife seen annoyed that we were asking after my mother is it not reasonable to have expected her to be out after leaving her for 2.5 hours. Why make appointment times if they don't mean anything. Why not tell us there are going to be delays. Sorry for the moan but mum had not eaten since breakfast and all the waiting on her own is stressful