I ain't requesting time off, I'm informing you of my absence.

"We are doing it the hard way. I came in to tell you personally because I didn't want to be rude. The easy way would've been an e-mail with a PDF of my employment contract, which includes how many paid vacation days I'm legally entitled to, and how I can use them." (note that this only works in countries with real worker protection laws)

Oh, no worries, they'll just call you constantly while you are on vacation because creating the proper structures to cover an absence costs too much and harassing you in your off-hours costs nothing!

Years ago I started a new job in January, having a trip planned in May for my sister’s graduation. At the interview I told them about the vacation. When I was being hired I told them about the vacation. When I completed training I told them about the vacation. Never was it an issue, until the week before vacation and they called mandatory overtime and said I could not go. I told managed they could reimburse me for the entire trip, or give me time off. They chose neither, I still went.

I once worked a really shitty retail job with someone who was hired on a 6 month fixed term as extra staff over Christmas peek, then got really salty with management when they declined their leave request for all of December and the first half of January so they could go to a rich person party town with their friends for the holidays.

The best part was when they turned back up at the end of January wondering why they weren't getting rostered anymore.