Seems to me like the reward was free gas.
If you've developed your system that the rewards card can provide a bypass to free fuel, your system is the flawed one and it isn't on the customer to provide feedback. This isn't a user testing scenario, they should have solved this bug before it went to production.
People aren't responsible for cheaply built solutions.
If we could make sure the ice being sent contains some form of the plague that all these rich idiots get, we could really do a whole lot of good real quick.