not in a million years
Not at any point; under absolutely no circumstances. Not in a million years did I think that I would actually win the lottery! A: "Do you think Samantha will agree to go on a date with Jake?" B: "Not in a million years!"
not/never in a hundred, etc. ˈyears
(spoken) used to emphasize that you will/would never do something: I’d never have thought of that in a million years.