Although most of the other comments seem to want to blame ZipCar for doing something unethical here, I have to say this kind of "random glitch" scenario makes t

Although most of the other comments seem to want to blame ZipCar for doing something unethical here, I have to say this kind of "random glitch" scenario makes the most sense to me. No sane company would want to rack up disputes with their payment processor for such little potential gain.