Everyone has an off day and you never know what people are going through who work in customer service.
I have a comment on the subject, but I also want to say that you use this line a lot. I don't think it's always relevant. With all due respect, and yes I know we're Christians and all that, but I don't really care what a person is going through when I place an order. If whatever you're going through is so much that you can't function well at work, then you need to speak to your manager about taking some time off. If you're well enough to work, then put your game face on, suck it up, man up, and do what you get paid to do. I mean, who HASN'T had to work while "going through" something?
I'm sorry, I just get kinda tired of hearing that line used as an excuse.
Now, on the subject, like most of us, I've been on both sides. I'm a consumer all day every day, and from time to time, I've played the role of the customer service rep.
I am very nice to customer service people even when they mess up my stuff. Now I'm still working on some things, and one of them is that I am very impatient when a customer service person is rude to me. That brings out the worst in me and I think it's justified, though I can still do better. I am slightly hearing impaired, and I get extremely frustrated when a person is mumbling or has a heavy accent, I ask them to repeat it and they either sigh like they don't want to, or get smart with their tone of voice... or repeat it with the same volume/speed so that I still can't hear them. I am already impatient and those types of scenarios make it even worse.
Also, one thing I've learned is that 9 times out of 10, the person you're annoyed with is not to blame anyway.
Another thing that bugs me about these people having a "bad day" or "going through" something: when a customer brings to your attention that you are wrong or they are unhappy, etc... apologize for it and be pleasant. I get stray calls from time to time with clients wanting to speak to my CEO because they are pissed. I never feel like talking to them, and my number isn't the number to call anyway. They are almost always rude and condescending and impatient and nasty. And the first thing I always do is apologize, even when they are being nasty to me. That's Customer Service 101. If you can't handle that, then call in.