4/14/25 AITA?

I had a meh meal of biscuits & gravy, plus a cup of coffee. With tax and tip (already included on the bill) the total was $15.46. I broke a 100 bill, and my change didn't include any coins. When I asked the waitress why she said, "Oh we just took $16 because we round up. No worries." AITA? Over a decade ago, the first time this happened to me I was surprised and a little aggressive about the coins due me. I'll recount that in a post to come. Today, I've 2 questions: 1) Has this ever happened to you? 2) AITA?