If requests are on HOLD, they must be released before they can be cancelled.
You can take the requests off of HOLD from the VMSCHED Expert Main Menu ;
8 HOLD Place a request on or off hold.
Take the request off HOLD.
Since they have already been cancelled, the request(s) will be deleted from the database at midnight or when the PURGE duration expires.
Although, you can recycle VM:Schedule to have them removed immediately.