Cannot delete unwanted Cron email send

Hi Andy,
In creating a rota “auto-email” I have mistakenly selected the wrong service – thus creating a cron job I don’t need.
I’ve tried to delete it, but though I am getting the report “Cron job deleted,” it’s still there in the list.
Can the delete function be fixed, please, or is there another way to get rid of the job?
Thank you,
Mark