I remember a mini-bar fridge in Manchester, England where there were sensors at the top that would add stuff to your bill as you took it out. Doesn't work so great when you push their stuff to the back to fit in your own leftovers. (Thereby getting charged for the entire fridge because the sensors went off) Then I saw that some of their stuff was on it's side (thereby resetting the sensors) to be accidentally knocked over again. I think they tried to charge me four times over for the entire contents.
But, I think the OP is right, it is a rip-off. I knew that the water was charged an outrageous price. But, I think that is because at one time in the distant past I was the OP's daughter, or almost. I think that for all of us, we were once like the OP's daughter or had been warned ahead of time.