You may have Reminders turned on in iCloud settings but that simply means all your Apple devices can see them. They are not backed up. In fact quite the opposite. Nothing sync'd to iCloud us backed up in the normal sense.
Calendar, Contacts an Notes have the recovery process in the linked article but see my last line above.
They appear to be gone. Logic says you deleted them
You can reach out to Apple Support directly. You should be able to reach them here
Contact - Official Apple Support
or phone numbers
Contact Apple for support and service - Apple Support
Feedback to Apple with a feature request or Bug report
Product Feedback - Apple