I got written up for letting my coworkers hear me go to the bathroom?

Anonymous
Let explain. I work in a drugstore, and no I'm not a manager. Yesterday we had a big rainstorm and a bunch of people called in, including the store manager. I was in charge because I was the only one on the floor. The store was busier than we expected, and we had 2 cashiers up front, one in beauty, one in electronics, and one other girl with me helping with the truck. Every 5 seconds, one of the cashiers would call for me to help them, find something, price check something, etc, on top of me trying to do my own job. It was hectic. I went 5 hours straight without a bathroom break after my big ass cup of morning coffee, so I sent a message to everyone that I would be in the bathroom for no more than 3 minutes. I got immediately bombarded with people asking if I could just quickly do something BEFORE I went to the bathroom, got stopped once on the way past the beauty counter, was sent a personal "urgent" message trying to undo my pants. I quickly told them nicely to stop and reminded them I was going to the bathroom. I took off my headset but I could still hear them talking, so I turned on my microphone and peed. It lasted over 30 seconds from how bad I had to go. I knew it'd be loud.
Everything seemed to calm down after that. I wasn't bothered as much and when I needed to go help, nobody would look me in the eye.
I didn't think it was that big a deal and it obviously worked, but when I went in this morning I got a write up. Now I wonder if I went too far?
Updates
11 mo
I want to add, not sure if it matters but they didn't believe that I was actually going to use the bathroom, they thought I was just going to "sit on facebook" cause they're older and thought it was just looking for an excuse. So I mostly did it to prove to them and to shut them up
I got written up for letting my coworkers hear me go to the bathroom?
10 Opinion