Finally ended the journey and received the PP today.
Mailed App Received: July 09
CC Charged: July 31
Certificate Received: Aug 05
PP Received: Aug 06
Office: Whitby
Best of luck everybody.
I think file number gets created at the time of data entry into the system and they themselves will enter it so I would just leave it blank. Do some more research or ask other members as well.
They just gave you the 20th day as a standard reply from the date of application received. Don't hold to it. Either today or next week your CC will be charged and following week you'll get the passport. 2 more weeks.