Yes there is. Select Designer Studio > Application > Development > Recent Actions. From the "Recent Actions" tab select "View Deleted Rules" then simply restore the Rules (including the Class definition Rules) you inadvertently deleted.
even the system generated records would (should?) be available for recovery. I wonder if this has something to do with the online exercise enviroment. Let's kick this off to email for a bit - then we will come back and post our findings here. I am going to send you a private message.