Bob, I want to believe you but there seems to be an anomaly with your report.
You said at first that the girl said your bill was for 4 beers and you had only three - so far so good.
After the argument the Manager came over and checked the bill to state the bill should be for 3 beers, not as the girl said, 4
But my question is, if the bill was a written note, how can there be confusion about how many beers were ordered and consumed between you and the girl and/or between the girl and the Manager.
Did the girl change the note from 3 to 4. Or if there wasn't a written note (bill), how could the Manager "check" it and make another judgment?