In 1996 I got kicked off an airliner (don't remember the airline) that landed from Frankfurt in Warsaw. I spent 26 hours sitting in an unyielding, hard-plastic, unupholstered banana seat until the next flight to my destination. I was offered no explanation (although I assumed it was overbooked) and no hotel or other compensation. I could not venture into the city because I had no visa.
I think international flights are more dicey.
I’m not sure how they handle them today.
Your experience was not good at all, and I’m sorry it turned out like that.