No Refills

I went to Subway the other day. It was the first time in Japan where they just gave me the cup and I could fill the cup with what I wanted. I thought to myself "oh, what a surprise, never been to a fast-food restaurant where the drinks are self-serve with free refills!"

But...I was wrong. They asked me what drink I wanted...I don't know why, since all they do is give me an empty cup so I can fill it myself.

Then, they added "Please remember that you can fill the cup only ONCE...no refills." And they had stickers saying "NO REFILLS" on all the drink machines.

So much for the free refills...I don't understand why they do it like this. Strange.