I wonder why they won't fill up your reusable cup. Maybe their cups are just the right size, and they don't want to give you extra coffee in another cup that might be bigger, but it's probably just pettiness because it's not one of their cups. I've been onboard the environmental movement since I was a kid, I can't understand why other people don't get it.
It's Americano which means they use shots of espresso and top it off with hot water so it wouldn't make a difference. Some of the really busy places have measured pours. In the case of paba they are just being annoying and stubborn.
I also can't get why people aren't on the environmental movement. Businesses are so wasteful because a customer complaint is painful. It's obvious most people just care about money, but it's sad and frustrating for the people who realize there is more to care about.