Dear Madame L,
I heard a cashier in the grocery store yesterday say, "Whatev." And I wanted to ask her, "What?" Except I knew she would not know what I was asking "What?" about. Also, she was saying this to an elderly man who was asking her a question, and I suspected she would be as rude to me as she was being to him.
Madame L welcomes you to the modern world of customer service in your local grocery store.
And, since Madame L is basically a kind-hearted person, she will explain for you:
This is how some people now say, "Whatever." It's shorter, see? And since these people are all very busy and don't want to spend too much time even showing another person how much they despise them for asking for help --- by, for instance, uttering one syllable more than absolutely necessary --- they say, with an extremely bored look on their face, "Whatev."
Best of luck,