They do give all the rules if you click the little tiny "terms and conditions" link at the bottom of the page. They also say that if you are not 100% satisfied, you can return any unused product within 30 days for a refund - same sentence they say "Satisfaction Guarantee Optimum benefits are most often realized with at least 90 days of continued use"
I didn't see anywhere about the sensible diet and exercise program though but they claim "instant healthy weight loss" but then in their comparison chart at the bottom of the page, so does "typical green tea".
My personal conclusion - if you want an overpriced concoction to make yourself feel pampered, it probably won't hurt you. If your primary goal is boosting metabolizm and getting antioxidents, plain old (cheap) green tea and a good eating plan is going to do the same job.