In AmE, if the server has brought the wrong food to the table someone at the table would say "I'm sorry, but we ordered XXXXX" or "This is not what we ordered, we ordered XXXXX."
When requesting that leftover food be packaged to take home, one colloquial term in AmE is a "doggy bag" (a pretense to the server that you are going to take your leftover food home for your dog*, and not for yourself. Even though it has long been acceptable to take leftovers home for your own consumption it is not uncommon to refer to the packaged food as a "doggy bag.") Otherwise, in AmE, the customer usually just tells the server "I'd like the rest of this (indicating the leftover food) to go**." As a matter of fact, the server traditionally asks the customers "would you like a box for this?" or "would you like me to wrap this up to go?"
*My own dog, the late great retired racing greyhound Trailways, was never the most intelligent creature when it came to learning basic commands like "sit" or "lay down", but he sure learned quickly what a styrofoam carry-out container meant. After the first time Mr. Ouisch and I returned home from dining out and I put the remains of my steak dinner (mainly just a T-bone with a bit of meat left on it) in Trai's dish he went berserk any time we walked into the house carrying a "doggy bag", whether it was leftover Chinese food or some
White Castle hamburgers. Mr. Ouisch eventually taught Trai not to "beg", so after his initial hysteria when we walked in with bagged or boxed leftovers, he'd dash over to his blanket, lay down and thump his tail and look at us with imploring eyes that said "See? I'm a good boy!" Of course, we always broke down and gave him a bit of whatever it was we'd brought home.
**In the US we usually refer to carry-out food as "to go." When I was in the UK I noticed that they referred to it as "take away."
