If it does not fully fund, you receive a refund from Kickstarter.
If it does, your funds go to the project, who are on their best effort to successfully launch the project.
You are NOT, however, directly purchasing a reward. You receive a reward as a gift for helping to fund at a given level.
But you ignore the bigger problem. How are you, as a Backer, able to require a refund because a Project breached its terms with Kickstarter?