a supposedly free-refill. this usually occurs when a restaurant or food court has manual fountain drinks, i.e. they just give you a cup and make you fill it up yourself at their soda fountain. in response to this blasphemy, you get revenge on said restaurant by not only filling up the drink you paid for, but getting refills as many times possible, FOR FREE.
Me: I'd like a medium dr. Pepper
Cashier:(hands me a cup, as if it constitutes as a dr. pepper)