The Holy Grail: Iced Tea at McDonald's

Twice in the last three days I have tried to order "Iced Tea" at McDonald's only to receive "Hi-C". The second time I enunciated as clearly as possible with a large separation between words. Can YOU get Iced Tea at McDonald's without sounding like a jerk by specifying that you want "Ah-iy-ss-d.......T-eeee", not "Hhhh-iiiii......SSSeeeeee"? I bet not.