There are a few forking circumstances when you can and should send food back in a restaurant.
1- If food you receive has something forking gross in it like a used finger bandage, packaging material, chewing gum, tooth pic or some other kind of not a food kind of object.
2- Burnt or really over forking cooked food.
3- Forking Raw or really undercooked food.
4- A Totally unexpected ingredient not revealed that’s something your allergic too or just don’t forking eat. I do note the RIGHT thing to do is to reveal all allergies or dislikes when ordering but sometimes these are surprises you don’t expect.
A difficult one to decide on is Seasoning. On one hand if you order something spicy and you are too forking  whimpy to eat it you are screwed, you Can’t send that back. If it’s slightly salty you sort of are forking screwed too but if you received a massive salt bomb or massive salt malfunction then it’s OK to send back.
Most times you really can’t send food back but if you do tell the wait person in a forking nice way. If they take something off your bill you should tip on all the forking food you received.
Have a Knife Day and see Ya Spoon!