You may see 'Adjusted Tiered Fee' billing rules within your defined rules which have no options to view, edit or delete:
These types of rules are from an older version of billing rules which cannot be adjusted or deleted within the platform. Existing rules will continue to function as originally defined however we suggest migrating to our Custom Price Books feature, especially if existing rules require updating as they provide greater flexibility and is easier to scale across all your customers.
If you have older rules you wish to migrate please reach out to support by submitting a support request. Older rules can be arranged to be removed once replacement rules are defined using a price book.