You could send a direct request email for that info to here:
accounts@soe.sony.com
Their Terms Of Service agreement does not state their policy between the time an account is canceled/forfitted to when they actually delete your info.
The beginning of the next billing period would also be my guess. I don't imagine they are quick to delete, your game purchase should earn you the right to saved information. It'
s your monthly fee that earns you the right to access it.
At this point, they probably are anxious to keep anything around that would insure your return. But how willing are you to risk all your efforts in-game on that thought?