What is the law about when to charge for an item and shipping?

I need to know if there is a law on the books about when a retailer/online retailer can charge for an item before it is shipped. Most retailers will only charge once the item is shipped, but I ordered from a company and they charged me that same day but the item still has not shipped more than 2 weeks later. I need to know the law on this matter so that I can complain with the proper knowledge.What is the law about when to charge for an item and shipping?
I don't know as though there would be a law on this. The retailer has the option to charge what they want, regardless. Check their website and look for the fine print in terms of shipping. It should tell you what is being charged to your card at the time of ordering, and what is being charged, if anything else at the time of shipping.