"Cancer and Parking"

My wife has an untreatable rare cancer, only 2 chemotherapy treatments available and neither worked. She had problems recently and was treated, obviously I visited - we had been told of parking concession, which states Oncology patients attending for treatment.

Coming home on the Monday night I was harassed by a staff member at parking desk with an attitude problem saying I was cheating the system, as they would not listen to me I left . 

The next night my wife was coming home after having had what treatment was needed, bear in mind she is exhausted and fragile and 70 years old and standing there having to listen to this person again telling me I was not entitled to this parking reduction. Their attitude was as if I was causing the problem out of choice saying we were not arguing it was all me.

I had read the wording on Derriford site by then and as stated my wife had treatment for her cancer complications, so why is is this person allowed to discuss patient's illness and cause distress to the patient - something should be done.