The discussion at the front desk never bothers me regardless of agents attitude. If I did not use/eat/drink it there is no reason to pay. What is insidious is the CC charge a week or so later. They know most people if they discover it will not dispute it. Also as a CC charge all you know is the hotel charged you for something else - it never says what.
I'll have to think about the Ambassador part; I'm of the mindset to contact my Ambassador only for really "important" things (ie. is my wife with me on the trip
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