I'm with all those that would have made an immediate stink to the rude cast member. I feel like Tommy Lee Jones in "Lonesome Dove", when he slammed the rude bartender's face into the counter... "I won't tolerate rudeness in a man". I'd happily push your chair, Crazy Legs.
We take my just-turned-90 year old grandmother to the parks a couple of times a year. She loves it there, and though there are very few rides she'll go on everyone has treated her like a queen. We've never had any problems, though the thought has crossed my mind to put a 'cow-catcher' on the front of her chair!