I use redbox all the time, and what you had happen to you (how the online res's are billed) is made very clear on the site. As a consumer, it is your responsibility to look into things-and it is not like this information is in tiny print at the bottom of the screen-it's right there! This is actually exactly what it says when you go to reserve the movie:

"By clicking "Checkout" I understand that my credit card will be charged for my first night's rental plus tax. The rental period for my title will begin immediately after the "Checkout" button is clicked, and I will have until 9:00 p.m. tomorrow to view and return the DVD. If I do not pick my DVD up by 9:00 p.m. tomorrow, it will be released for other customers to rent. I also agree to redbox's Terms of Use."

I think they do it this way (charge up front) because the box may only have 1 or 2 titles of each movie in it-if you could reserve it without paying for it, it would hold it for 24 hours for you to pick it up and not let anyone else rent it. Then you don't pick it up. They just in theory have lost out on the sale of anyone else who wanted to rent that particular movie from the machine. When the charge you up front, it gives you incentive to pick up the movie.

I do find it annoying that you can't reserve more than 1 movie at a time, it has to be a seperate transaction, but only from a user-friendly stance.

I don't think they will or should do anything for you. It is your responsiblity to make sure you have enough $$ in your account to cover whatever it is you are purchasing.