I can't believe the customers are so nasty! Goes to show you people with money who stay at 5 stars are not happy, money can't buy happiness. These people are just plain rude, and you can't take it personally, you are just the scapegoat.
Why can't you say-I am a human being and deserve to be treated with respect. I will do my best to solve your problem, but I do not have to take your abuse. I will assist you when you have calmed down. I've seen hotel personnel do that. I don't see how management can allow you to be abused like that.