See, I think the entire customer service industry needs to change and people should be able to call out others for being dicks. I get you don't want to piss people off and lose business, but by pretending they're not pieces of crap, you're enabling them and it has to stop somewhere.
Telling someone they are a piece of crap will not resolve the situation, especially not in customer service. It's just not worth it. Either they are having a bad day or they are a horrible person. Being rude won't fix either one.
it's a joke, don't get offended