"Wrong doctor allocated"

I was referred to London Independent hospital for ankle pain. I waited for 3 months and then receive an appointment. On Appointment day I was told that they mistakenly put me in a list of knee doctor. I have to wait another 2-3 months to see the ankle doctor. I told them particularly that its not my mistake and just because of their mistake it has wasted 3 months. I found the staff to be unprofessional and they did not even seem apologatic for this. Completely disappointed from the service and staff.