"Cancelled appointment"

I had an appointment at QM Eye Clinic on .10 April. We arrived an hour early to be sure of parking and finding the place. On arrival in the department we were told the clinic had been canceled. No apology or explanation. We were handed a leaflet and advised to complain. I wrote a letter addressed to Patients relations Department on 13 April and to date have heard nothing further. I am now left in limbo wondering what the next step is. Any suggestions?