On rare occasions the amount you get charged may be higher than you expect. This is normally due to your bank or card issuer charging an additional Cash Advance Fee when a credit card is used (the fee does not exist for debit cards). This happens when your bank decides that your payment is a Cash Transaction. Xcoins does not have control over this charge. If this happens, you should contact your bank and ask them to refund the fee they charged you.
Be careful to avoid misunderstandings with your bank or they may accidentally file a payment dispute, which, if not managed properly, could damage your credit rating.
If you would like to avoid being charged a potential Cash Advance Fee, you should use a debit card when buying Bitcoin with Xcoins.