I've ordered pizza a few times and it never goes as smooth as it should be



I went recently to McDonalds (drive-in) , I asked for a Happy-set and the guy replied something I didn't understand, asked again and thought that there were no happy-set available so I asked for a sandwich ... at home, opened the bag and found a sandwich and the happy-set contents *but* not the colorful happy-set box ... that was what the guy was trying to say.
My japanese is somehow between 4kyu and 3kyu , that is I'm not anywhere near fluent so I always try to *predict* what is any conversation going to be about. If I go to McDonalds I know what to *expect* , cola? ice-tea? milk or lemon? fries? size (S-M-L)? "please advance and pay" etc ... Not having "the box for a happy-set" was totally unexpected.
That's why I think examples from real life with unexpected situations will help a lot.
I saw thig guy at one Hokka-Hokka store going straight to the cash register and said "kore" while pointing to the picture of some bentou in the menu and then holding up the same finger saying "just one" and then moving his head up and down when asked if that was all. ... It's great when everything goes as expected doesn't it?
Regards
Quique