http://www.cineplex.com/Promos/coke.aspx
Various Coke, Nestea, Sprite can packages will have these B1G1 Free Cineplex Movie Codes/Cpns on them.
Valid from March 7, 2016 - June 30, 2016. Online redemption only.
Rexall has them advertised on the front page of their flyer for $ 3.49 for 12 cans . Other stores should have them too.