There's a reason writers say "Be careful or you'll end up in my novel," and here it is: We like to take truth, and real-world experience, and put it to good use. Sometimes we even embellish it. (We like flair, especially in prose.) This means I'll, somewhere, tuck an impolite government-office employee like you into a book I write.
You should know that, to explain this character's consistent and unsettling attitude, I'll build him as such: A 40-year-old and (always) single man who lives with his overbearing mother, finds himself gelled in the center of a mediocre career--wherein he treats his customers as if he's doing them some grand favor, when in actuality it's the whole of his job description--and who leads a sad and unsatisfactory life.
This is the kind of picture you paint. Or, at the very least, it's where you point my imagination.
Sir, would you have guessed you are good fiction fodder?
I do feel for you,
and I wish you the best (even though I cringe when I see it's you at the counter),
might even offer a holiday prayer for you,
who only wants pleasant respect
but also a good story on paper