Assuming you are in the new Appsuite email format, open the address book from the Inbox page. In the left pane click on "Collected addresses". If you had the settings at default, you should see addresses you either sent emails to or received emails from. At the top of the list click on the "Select all" box. Then in the toolbar click on the "hamburger" icon. In the menu you get click on "Move" or "Copy". In the next window click on "Address book". Then click on Move at the bottom of that window.
I have not tried doing this myself, but I'm thinking it should work, although I don't know how much data will get moved. The old address book actually had a series of backups you could resort to. The new one, unfortunately, does not have this ability. Other than that, you could call Comcast security and see if they can restore your contacts-------------------
Comcast Customer Security Assurance-------------------
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