Where on earth is that a policy? Sounds like the reason your customers are complaining might be because your store is the only one doing that.

yeah those are supposed to be filled to the top lol

policy is to fill it to the top in lattes with milk, in refreshers you do extra base and extra milk/water/lemonade (you can find the standard on the drink recipe cards), ect. only left unfilled if they do the “hack” of trying to get a latte by asking for a splash of milk on an iced espresso (but in that case you can do extra ice to fill the cup)

for stuff like refreshers or lattes yea you fill it to the top if it’s not iced… the only times i don’t fill a drink to the top is if someone orders smth like an iced doppio espresso with extra milk or a tall tea in a venti cup.

Is this a thing?

Well they’re probably complaining because every other store follows the complete opposite policy. Nowhere is it stated that light ice/no ice should be left with room. In fact, the resources we have available state the complete opposite.