I've noticed だと showing up after verbs for a while now in various forms of media, such as blogs, anime, regular TV shows & also when speaking to Japanese people. However, I was originally told that this grammar is incorrect, as だと can only be used after nouns - so what is going on here?
An example from a manga/anime called prince of tennis: Character realises he is about to get beaten up by another character - in bid to stop it happening he says: なんでもします! To which the other character replies (angrily) なんでもするだと！？
Thanks in advance to anyone who can answer this question.