While studying abroad in Paris, I went into a Monoprix (think of a French CVS) because my classmate needed to grab something last minute.
It was late, but we thought we'd pop in and grab what she needed super quick. When all of the sudden the music and lights go off.
The staff were locking the doors and leaving for the night. And since we were all the way at the back of the store, obscured by the aisles, no one had seen us come into the store.
It must have been really freaky for those workers to hear a disembodied voice (mine) from the back aisles scream in English: "WE’RE ABOUT TO BE LOCKED IN HERE BECAUSE YOU NEEDED TOOTHPASTE!?!"
Needless to say, an employee popped his head back and saw us. I rushed my classmate to the checkout and hovered until she'd handed over her euros. We walked out of the store and the doors whooshed locked behind us.
My classmate thought it was hysterical. I don't think anyone has ever laughed so hard while I glared at them, whispering in a Franglais: I would have been so pissed if my study abroad concluded with me trying to figure out how to call and be released from a French convenience store.