> It is not reasonable for them to say "sure, here's your alcoholic drink as you requested" and give them an alcohol-free substitute without telling them.
Your analogy doesn't work because: - they tell you the rules at the entrance of the bar - they totally tell you when they give you a substitute
The only issue is the bartender asking you for your money before serving you the drink really but again, this is known since day 1 by the customers.