I would suspect if you ever took a chemistry class, you would understand that to add milk of cream to coffee, the total volume expands. Thus they left you enough space for1/4 cup of 'cream'.
I'm sure if you explained that you only wanted 1 oz of cream they would have provided you with more coffee.
I'm not sure why you are reporting this to the whole starbucks world on yahoo.
I have. It's a cute trick they pull. Tell them to fill the cup, you want every drop you pay for and pour what you don't want out. I once had one of the clowns tell me I made the garbage heavy. It's fun laughing at the wimps.