Just saw this advert on Facebook. The promotion is valid for NEW WOOLWORTHS REWARDS MEMBERS ONLY. For existing members, I don't see why you can't sign up for a new account to get the $10 credit then dump it afterwards.
Sign up by going to given link and then clicking the top "click here" url to receive $10 shopping credit by Feb 11 2017. As people have commented, while the promotion is intended for Facebook users only, anyone appears to be able to sign up!
Valid for first 4500 signups so it may not last long, or til Feb 1 2017.