The borrowed
2013 points will remain in your 2012 use year and will need to be used for stays prior to October 1, 2013. Banking and Borrowing are final transactions.
The
2012 points....
If you cancel the September reservation before your banking deadline (May 31, 2013), those points are returned to normal status and can be banked.
If you cancel after May 31, and prior to 30 days before the check-in date, those points return to normal status, but must be used prior to October 1, 2013.
If you cancel 30 days to 1 day before check-in date the points go into holding status, basically, in your particular situation, again meaning they have to be used prior to October 1, 2013.
If you cancel day of check-in, all points are considered used and will be lost.