Thanks for the clarification. I also don't get the paper anymore but do get a handful of flyers. I will look and see if this was one of them.
Now that I looked at the ad again on Reddit, the 15% off Xbox Live credit offer at Dollar General might only be restricted to the $25 Xbox cards since that's the specific card that appears in the ad. I should have paid closer attention. If anyone is able to get 15% off the $25 card at DG, please post!