This M&Ms Vs. Chocolate Chip Confusion

I went to McDonald’s for an M&M’s McFlurry. I said, “Hi, I’ll have a chocolate chip McFlurry.” The cashier responded, “Uh, we don’t have chocolate chip.” I was staring at the M&M’s in confusion and said, “OK, I’ll have a chocolate chip McFlurry.” They repeated, “Ma’am, we don’t have chocolate chip. Did you mean M&M?” I never went to that McDonald’s again.