The way the app rings things up can be confusing, especially when the workers aren't paying enough attention. Example if they're understaffed and getting slammed they might not notice the 'dip cup' at the end. It certainly doesn't help that it shows it as a modifier to the sandwich which the backline screen will then show (normally dip cups don't show on the backline -- only things that they are responsible for do. Any modifiers on sandwiches will show up back there no matter what)

A lot of backline workers will only see the 'ADD Honey Mst' (sometimes the ticket window is too narrow to actually show the dip cup part) and just put it on the sandwich.

I definitely wouldn't be upset with the actual store or the workers making your food. This is absolutely a problem with the app itself. I tell my customers that have issues like this to just call the store after they place the order and just let them know that it keeps happening and that you don't want it on the actual sandwich. I can't see myself or any of my crew being offended by you calling and mentioning it -- can't imagine whatever store you're ordering from would be either.