Lisa,
Yeah, GMAC should be understanding with your situation. Hopefully they let you in for another shot without having to repay.
About the Veritas course...it really depends. If you can pull a 40+ in the verbal without any more help, then I would stick to the math course and save some money. If, however, you really want to fortify both your verbal and quant skills, take both.
I'm not too familiar with the weekend course, but I believe it doesn't give you the full material like the full course or the intensive courses do. Not a big deal, just make sure you know what you're getting before you sign up. I actually took a week of "vacation" from work to take their intensive course.
One last note on the course. For the quant instruction, they are not going to re-teach you the fundamentals. You have to go in there with an understanding of the basics in math to get the most benefit out of it. If you don't understand the basics, some of the stuff might not help you as much as it should. Good news is you can learn the basics fairly quickly and there are plenty of sources to do so (books, websites, etc.).
If you end up taking the class, let me know how it goes.
Artis