Some people want to create a new punctuation mark to express a surprised question, called an
interrobang. But, really it's not good to use it or anything like "!?" It's better to just express exclamation using context, and use either an exclamation mark or a question mark depending on what you want to stress.
"What the hell?" The phrase itself expresses exclamation. A question mark is all you need. But the question mark gives it a bit more of an interrogative tone.
"What the hell!" Again, the context makes it clear it is a question of sorts, but really it is more of an exclamation, almost as if the person quoted is shouting, angry, and is not asking a question so much as expressing emotion.