Today, on 07/11, between 11am-7pm, walk into any 7-Eleven, while supplies last, and get a free small Slurpee. Offer valid in Canada and the US. To see which flavours are kosher, ask to see the syrup in their "syrup room" on which you can see the certifications.
Download the 7-Eleven app from the Google Playstore or iOS, and buy 7 between July 12-18 (and scan the barcode with the app), and get 11 free slurpees until August 31st! Normally, with the app, you get 1 free after every 7.
Here's the 7-Eleven store locator link. Watch your feet--they could get VERY sticky by the dispensers!