Why has my credit card been charged twice?

Almost 100% of the time, when a credit card shows two identical
charges, it is due to our customers making two orders. One order
failed, and one order was successful. For example, a customer will
attempt a checkout, and accidentally enter incorrect information. The
customer clicks submit, and receives an "order error" screen. The
customer will then go back, and correct the information, which results
in a successful order. The customers credit card company will attempt
to send funds on both orders, which shows two identical fund transfers.
Our store will ONLY accept the funds being sent where all the
information was accurate. It will refuse the payment where the
information was incorrect. As soon as your credit card company notices
that we refused payment, it will credit your account. This process,
depending on your credit card company, can take 3-5 business days to be
resolved automatically. If it does not correct itself within 3-5
business days, or you did not receive a "order error" screen, please
submit a support ticket.