Wild bean café - Cups half full but full priced

Hi, I've been trying to just over look iet everytime bit now it has happened one to many times.

I absolutely love Wild Bean Café's beverages but last time i purchased a Bar one Hot Chocolate the cup we're almost only half filled, the rest was froth.

I could've just purchased a small hot chocolate but i got the large one half filled.

Its not the 1st time this happened :(