Double charges on Credit cards happens very infrequently, when it does, it is usually because either,
(a) the user has closed the browser or clicked the back button while the credit card charge was in progress, or
(b) the third party payment gateway that processes the credit card transaction took too long to respond and resulted in our system timing out.
The credit card charge will be reversed to you within 2 to 3 days from the date of your transaction attempts. We would suggest you to contact us if the amount is not being credit to your account in 2 - 3 working days. We would be happy to help you.