"Disappointment"

My appointment with the physio department was canceled in July due to the consultant being unwell. The new appointment came for a date in September which was fine at the time and due to another appointment coming in on the same date I tried to rearrange my physio appointment. I rang up the number given on the appointment sheet and the agent was happy to change it to today at 9 am. when I arrived today at 9 am I was told it was yesterday at 9 am but I had it written down on the appointment slip. After a little while someone came to me to offer an appointment for tomorrow which was unsuitable which I was disgusted with after making my way all the way to the hospital to be told this.

What could be improved? Willingness to accommodate my appointment.