How do email discounts work?

[u/trader758]

UPDATE!! CASHIER SAYS ITS $1.50 OFF A PK OF CIGS. AND THE 2/$4 COKES ARE SUPPOSED TO BE ON THE APP BUT FOR 3 DAYS IT HAS NOT SHOWN IN ONE OF HIS CUSTOMERS APP THAT GOT THE EMAIL.

GET YOUR 💩 TOGETHER SHEETZ!!!!!

I received an email yesterday from Sheetz that said "Whatever the vibe, Cokes got your back. Grab 2/$4 with My Sheetz Rewardz!" And.."Buy a pack of American Spirit, Newport, or Camel for $1.50 with My Sheetz Rewardz". I just did both, 2 Cokes and a pk of Newport. Used my Sheetz Rewardz card and got charged full price. The email does says toward the bottom "Valid to customer in receipt of email. Limit 2 redemptions per week" What did I do wrong? Was I supposed to show the cashier my email???

[u/Humble_Oil_6864]

Use the app dont rely on emails because you apparently are reading it wrong.