There are usually two reasons why a payment is declined even though the funds are available. The first is an address conflict as the address you enter when enrolling must match the address associated with your credit card. The second is a daily dollar limit or fraud filter attached to your card. Sometimes your credit card provider will add this filter to your account for your protection without telling you. If your transaction is declined please contact your credit card provider and check both these situations with them. You can also write to us at firstname.lastname@example.org to receive further assistance and make sure that your spot is held while you complete enrollment.