They shouldn't be replacing an old cup with a new one... same with refilling a non-KI cup, the $2.12 is a discount for refilling a KI souvenir cup that you paid $10 for, not for refilling the water bottle you got at Dollar Tree. It's not the "people who take their jobs so darn serious" who don't do it, it's the people who don't think the guests should to be able to get away with whatever they want. (I personally can't believe they replace current year's ones... if I bought a water bottle at Walmart and then dropped and broke it, I certainly wouldn't expect them to give me a new one for free!)
Oh, and maybe if you took your job seriously, you would still work there.