FREE Slurpee At 7 Eleven (Text Offer)! This post may contain affiliate links. Please read our disclosure policy here.August 29, 2014 by Sia Here is a great way to head out of summer with a bang! Right now you can text SIXFLAGS to 711711 to get a coupon for a FREE Medium Slurpee at 7-Eleven! Find more restaurant coupons and deals here too. Thanks Money Saving Mom!