My sister and I went to the UDF for ice cream shakes, and I sent her to order mine while I got ice and my mom's Diet Coke. Sister calls me over to tell me that the clerk refused to make my shake. When I asked the clerk why, she said she's be glad to make me a mint-chocolate shake but couldn't make me a hot fudge mint shake. I asked her if they were out of hot fudge - she said no. I asked her if they didn't offer those shakes anymore. She said, "No, we still have it." I asked her why then she couldn't make my order. She stated that no one who ordered it liked it, because the hot fudge melted the ice cream. I told her I knew that - and chocolate syrup didn't taste like hot fudge, I wanted the hot fudge, would she make my shake now? She again refused.
It's (somewhat) amusing now - but at the time? Manager got a call the next morning.