What If Your Study Permit Has Already Expired?
This is where things become more serious.
If your study permit expired before you applied for an extension, you have lost your student status.
You generally need to apply to restore your status as a student and obtain a new study permit.
IRCC says you normally have 90 days to apply for restoration. You also can’t continue studying until your status has been restored and you’ve received the new study permit.
So if your permit is already expired, don’t simply continue studying and hope everything works out.
Go get the situation addressed properly.