Places don't stay in business very long if they give away the merchandise.
So, no it is not common for the situation to come up. Giving away stuff is not usually considered a compliment either.
A bartender would say "thank you" or "please come again" in order to show his appreciation for your business.
Is it customary in your country for businesses to act like they are not going to charge you, and then the customer must insist on paying?
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