If you want to try to convince the court that you didn't get notice because it wasn't in writing, you are free to do so. But no, that's not going to work, as you actually accepted both the notice and the return of roommate's portion of the rental unit.
If you are choosing not to try to mitigate your damages by replacing him as a tenant, he can raise that as a defense to his owing you so much as a penny of rent.Quoting Aquarius9217
You haven't bothered to give us any dates to work with, so you're going to have to figure out the relevant dates for the notice period for yourself.

