С-201

HE СКАЖЙ(ТЕ) coll indep. sent these forms only) (used to express an objection to or disagreement with what the interlocutor has said) you are not quite correct: I don't know about that Pm not (so) sure (about that) I wouldn't be so sure (about that) don't be so sure I wouldn't say that.

Заговорили о немцах... «У них в общем (патрульные) пары не так крепки». - «Ну, не скажи» (Гроссман 2). The conversation turned to the Germans...."Their patrols don't stick together like we do." "I don't know about that" (2a).

(Лукашин:) Ну, а я представитель самой консервативной профессии. (Надя:) Не скажите. Мы с вами можем соревноваться (Брагинский и Рязанов 1). (L.:) Well, I'm a member of the most conservative profession there is. (N.:) Don't be so sure. We can offer you some competition there (1a).