Asserting Myself as I Order "Large Coffee" in NYC Coffeehouses

Lately, I've experienced at least 3 times being misheard for ordering "large coffee", and the barista would give me 'iced coffee,' instead. The last time this happened, I flared up a bit and heightened the tone of my voice so everybody within 5 feet distance from me would hear what I wanted to say.

"I said, 'large coffee', not iced coffee. Is there something wrong with the way I pronounce it?" and in exasperation, "I'm sorry, I have a different accent," as I tried changing my tone in an instant (laughing somewhat in my mind and imagining how amusing I must have looked before them).

But the barista already apologized to me by quickly saying "I'm sorry. It's OK, I'll get you what you ordered" (or words to that effect), and in a few steps and less than 5 seconds, handed me my 'large coffee.'

And myself, being annoyed, said aloud "It's getting to be disturbing; this has happened to me at least twice." And I noticed one of the owners (or probably a manager) gave a me a look, but smilingly said "We're sorry (again, 'words to that effect' as I would not want to hear anymore words from them)." I just wanted to leave the  place as soon as possible, or else, I would be saying something more ugly to create an effect.

I just wanted to make a point. I can only imagine why they would mis-hear me. I hope I'm wrong but maybe because I look different from their usual customers in the area. Even those 2 guys in suits standing at my side paid attention to me when I asserted myself. Or most of them in that coffee shop must have thought I'm hispanic or something similar, just like those 2 or 3 guys I noticed helping inside the kitchen. Or is it just me imagining these probabilities with implications because I've got my own set of biases and prejudices, too? Whatever; I know I'm fine and happy having my cup of coffee as I switched my mood. It can happen to anyone here in NYC, I suppose.  I can only wish most would be exposed to other kinds of people in every moment of their lives here so they'd know how to listen and listen very well. And there would be no need to tire oneself over such a seemingly petty but really important matter when one is in business as serving coffee.