It has ben 2 days since the 50% off coupons expired. Give them some time, IU would not expect anything until 2 weeks to 1 month from this past Friday9 so 6/14 earliest and 7/1 latest).
To quote the email that the 50% off coupon came in:
In addition, next week we will be sending out a second coupon that will give users 20% off of any game or application on Impulse. To help encourage an active Demigod community, we will be occasionally be sending out additional coupons to active players of Demigod (people who play more than a couple of hours a week).
That email came the week of 5/22, so the coupon should have come last week.
