Actually, you're paying a blanket price. People who get skim milk pay the same as people who get whole. It's all accounted for (except for extras in some places, like whipped cream and sometimes soy). Like it or not, this kind of stuff happens in coffee shops. The "ethics" of coffee-making (particularly in smaller shops) really aren't that stringent, and if you don't notice then they're gonna keep doing it (especially in the "pregnant woman gets decaf" scenario). It's a little bit like if you go to McDonalds and order a plain hamburger, but you get it and it has ketchup and onions and whatever. You can go and complain and raise a stink about it, but mostly what happens is the managers shrug it off, take your sandwich to the back and scrape off the toppings. You didn't pay for a "plain hamburger" specifically, you just paid for a "hamburger" with the preference that it be plain. Ergo, BBB doesn't care, managers don't care, and lower-level employees sure as hell don't care.

Op's a girl dumbass