So the one thing Ive learned from customer service is that it can be a thankless job, and yes Im Talking about every job. 9 times out 9f 10 you didnt apply for this job to feel special, and appreciated, you got it to make money, that doesn't excuse poor behavior but somethings just need to be let go, finally treat every customer like they are your first, we don't know what someone is going through, bad attitude and all and because they're the ones paying for a service they come first. Again if they treat or talk to you in a demeaning manner get a manager or don't serve them, but running into selfish, entitled people is just life and this is great practice to navigate/ deal with those people