Chowking unforgettable lines

On the phone:
"Miss, isang plain congee.". Miss said, "Wala kaming plain congee, beef congee lang." (Huh?!)

Over the counter:
"Miss, isang Halo-halo petite.". Miss said, "Fiesta lang po available". (Eh?!)

Argument:
X is a subset of Y.
X exists if and only if Y exists.
Therefore if Y exists, X should also exist.