YOU SAID:

my dad left for milk 20 years ago and never came back

INTO JAPANESE

私の父は20年前に牛乳を食べに行ったことがありません

BACK INTO ENGLISH

My father has never been to eat milk 20 years ago

INTO JAPANESE

私の父は20年前に牛乳を食べたことがありません。

BACK INTO ENGLISH

My father has never eaten milk 20 years ago.

INTO JAPANESE

私の父は20年前に牛乳を食べたことがありません。

BACK INTO ENGLISH

My father has never eaten milk 20 years ago.