"Patronised in front of onlookers."

I was very anxious about my appointment, and turned up on the wrong day in error. When trying to re-arrange my appointment for another time, a different member of staff came along and lectured me in front of the waiting room with people in it, telling me (despite the fact that I had had an appointment, and was attempting to make another) that it was not a drop in or walk in centre, and that I had to have an appointment. I was embarrassed, patronised and humiliated and just wanted to, and did, leave without making another appointment as a direct result of this one woman's treatment. I had not met or seen this person before (and hope never to again) she knows nothing about me. but would appear to have made judgements based on?