I need a report for orders which have got cancelled of confirmation.
There is no standard report in SAP which shows Report for conformation cancelled.
But you can check in order it self in COR2 good movement details.
Or check document in MB03
Use CORS to reverse the phases.
After canceling if you want to view it again then use CORT (here there is one check box named 'Reversed' means that phase is reversed).
Or Please use user exit
EXIT_SAPLCORF_404 Process order conf.: Customer specific input checks 2