Dear,
Please go to KKF6N transaction select your product cost collector and go to Edit -> Deletion Flag -> Set menu options then deletion indicator and try the same.
When you flag a product cost collector for deletion, it receives the
status DLFL (deletion flag).
When you set the deletion indicator for a product cost collector, it
receives the status DLT (deleted).
I hope it will work for you.
Regards,
R.Brahmankar