Yes, you did the right thing,
You did as much as you could and even more by confronting the clerk.
Personally I would call the owner/manager and tell him what happened. I doubt they would be pleased.
It was a mean and discourteous thing she did. If I saw one of my employees doing that to a customer, she would be fired on the spot.
Being in the 'customer service business' means just that. You provide service, not entertainment at someone's expense.
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If you have one option you have an obsession.
If you have two options you have a delema.
If you have three options you have a choice.
Look for three or more options.
"I'm not too crazy about reality, but it's the only place to get a decent meal.