As others have stated you will get them back.
17.1. A fee as specified online at ba.com will be charged if flight bookings for Reward travel are cancelled by the Member prior to departure. Provided a cancellation is made more than 24 hours prior to the scheduled departure of the first flight in the Reward itinerary the Avios Points charged for the Reward will be re-credited to the Member's account. Avios will not be refunded for partially flown bookings.
http://www.britishairways.com/en-gb/...&link=main_nav