It’s Saturday, they don’t work the weekends.
Let me ask, what are you using on and how did you cancel? In other words, did you sign up for the subscription through iOS, Android, or Desktop? If it’s iOS or Android, subscriptions are handled through their app stores and you should see cancelled subscription there.
If you did it on Desktop, then your subscription would be visible at https://account.brave.com/
I just tested and was able to receive an email to login. Once I did, it shows my status such as below:

See on the top that it shows it was canceled? And if not, then where it says to Renew Plan it would have had the option to Cancel.
So yeah, can you clarify what you’re attempting to cancel on and how you’re trying to cancel? And you haven’t said that you didn’t cancel, but the complaint is only that you don’t see a cancellation email? (I’m not sure if I remember ever getting one either, meaning they may not send cancellation confirmation but instead just confirm it in your account)