Nice looking bar with what was initially a nice afternoon break sipping a couple of chocolat viennois and two pieces of cake (lemon and chocolate). Chocolate drink was so good that we decided to order a second one only to be served a "a l'ancienne" version nowhere near as good and more to the point extremely bitter. We made a remark to the waitress who said let me see what I can do and later dropped the bill without amending a cent to the total. I proceeded to challenge her and tell her that it had been clearly their mistake to serve us a different version of what we initially ordered and already consumed once and that it would have been more elegant of her to explain she could not make a gesture rather than bet that we would not notice and get away with it. She replied she did not have authority and would have to ask her manager but he wasn't around... I replied that it was clearly none of my concern and for her to discretely sort it out and at least communicate to us the basics. At 12 francs per hot chocolate one expects faultless delivery in a five star hotel. The worse is that she did not prepare the second ones and that her more senior colleagues threw her under the bus to disguise their own mistake. Poor show and unacceptable for such an establishment. Hence the low rating.