I worked for years at a high end grocery store that catered to uppity, rich, white women.  However, this shit never happened.   Not once.  You get this kind of behavior from uneducated, lower class people, not rich snobby ones.  They will ask, and when you tell them it can't be done, they try to sweeten the pot -  buy the result they want, because that is how their world works.   The only believable part was the DYKWIA.  They ALWAYS throw this out when the "buy the result" doesn't work.  Then, after they use the Buy it and the DYKWIA, they shrug, and take whatever they can get.    We were trained to offer options at all times - instead of "We can't do that", you say, "Oh, an order that big for that type of food would require a couple days notice.  What I can do today is make you 2-3 of those giant subs - that will take me about 1 hour.  Or, better yet, I could slice up a bunch of cold cuts and cheese, and you could have a "make your own sandwich" spread.  That would be fun!"  Always make everything a positive, and you won't deal with this shit.  The fat was lazy, didn't want to work, and threw attitude and negativity to the nice women, and then wonders why they responded negatively.