Usually just contact the store and let them know. If their customer service is any good they will quickly void or refund the duplicate charge. Worst case scenario you file a chargeback with your credit card company.
how many people here are using a credit card for online shopping? do you experience double charges? how do you deal with it?
One way creditors double billing cycle method of calculating finance charges. This is one of the most expensive ways to calculate your finance charge may be. Calculate your finance charges, creditors present and previous billing cycle average daily balance for your uses.