あっけじゃありませんでした
呆気じゃありませんでした
akkejārimasendeshita

Noun
Desu Copula

The polite, past negative form of あっけ

1. Was not foolish.; Was not silly.; Was not dumb.; Was not clumsy.

Past/Perfective
Negative
Polite
Terminal Form
Usually Written in Kana