それならそうと

expression

even so; still

Expresses frustration or impatience when someone fails to act on what they already know or should have done. Often used to prompt action or point out a contradiction.

• それならそうと、なぜ早はやく言いわなかったの？

  If that's the case, why didn't you say so earlier?

• それならそうと、すぐに手伝てつだってくれればよかったのに。

  If that's how it is, you should have helped me right away.