You can recover a deleted note prior to the 2 weeks the note will be permanently deleted. The system will email you about 2 to 3 days prior to the note's pending deletion, which is permanent.

Go to the client's page and click the "Notes" link on the left (or the top portion of any mobile device's screen).

Then click the "Recently Deleted Notes" link at the bottom of the Notes page.

Then you can select the "Recover" option for any note you wish to retrieve.