If you are a Subway eat fresh club member you should have received a SMS about this offer:
Details: Purchase any 2 SUBWAY FOOTLONG® SUBS for $15 after 5pm
Valid at your chosen store for 24 hours after activation.
Available until 11/11/2012.
Otherwise you can register here to get the free membership
http://www.subway.com.au/EatFreshClub/UserDetails.aspx
2 SUBWAY FOOTLONG® SUBS for $15 after 5pm