While I am a grandmother of many, I have no patience for unruly children in public. I believe that an upscale restaurant has an obligation to it's clientele. They should have a rule that no children under 5 are allowed after 6PM or something to that effect. I did, on one occasion, write an e mail to a restaurant explaining that I had come for dinner and had to listen to a screaming child all evening. Since it was a large restaurant I wondered why people with children couldn't be seated in one area, while those without were seated a distance away. I got a lovely letter of apology and a gift certificate to be used toward a future dinner. I would certainly contact the restaurant and explain exactly what you posted above. While it is JMHO, I think they are obliged to provide a certain ambiance with the food.