Take2, you're asking the right question: Did you handle it as well as possible? The answer is yes, now put it out of your mind. There is a species of human that has learned if they bitch enough, they get what they want. They specialize in making people feel badly for telling them "no." You dealt with it properly, now move on to the next problem.
Last night I sold out for "Amelie." I'm a hundred-seat art house (50k pop. university town), I was here alone. After I get the show on the screen someone I know as a cronic complainer walks in and wants into the show. I have a lit-up sold-out sign with a flashing stobe over the door. Even Ray Charles couldn't miss it (apologies if that offends anyone, but it makes the point nicely). She wants in. I tell her were sold-out. She goes into a diatribe about it being a crime that a "sh***y little theater like this gets such a popular film since we're too small to service the community." She was crusing for a free pass, I guessed. Instead, I said, "This conversation is over." Then I went up to the booth. I watched her blow out of the place in a rage on my security camera. Felt serious pity to whom ever she was going home to that night. There will always be an element that will never get it. Never give them more time than they are worth.