What you are likely seeing is what is called a "Pending" Charge. This is the bank's authorisation that there are enough funds available to place your order. The only thing your bank is verifying is that the credit card entered has the funds.
We validate the billing address and card verification id for your own protection to try and ensure that the card is not being used fraudulently. As long as the credit card number is valid a "Pending" charge will appear to hold those funds. Your card only gets charged when the actual product ships. "Pending" charges will usually be removed from your card within 3-4 business days.
In the event that you tried unsuccessfully to place an order and have several pending charges contact us on 0508 200 300 between Monday and Friday 9am - 5pm and we will look into having these removed.