were you a pr/citizen during this time you speak of?
This “old” benefits you are speaking of, were you already living in Canada with your under 18 year old child?
what do you mean by you did not receive it?
from your posts, it does not seem like you have been filing taxes. No expert here but yoy need to file taxes to be eligible for benefits is what i know.
The new version child benefit is also relatively new and wasn’t available many years go. Assume you are interested in the monthly payment per child. You can’t go back years and claim the benefits. Not sure what situation you are in if you are asking about claiming benefits from so long ago.