Thanks for your question about deleting and overwriting pages. Are you certain you are editing the same page? If you deleted the Contact Us page it must have been emptied from the trash. Or, are you uncertain as to whether or not the page was deleted originally?
Remember that if you want to start over in BoldGrid there is a dedicated button that will delete all content. You can find this option under BoldGrid > Settings > Start Over, from within the admin menu.