Credit cards can be declined for a number of reasons. MeetJune isn’t notified of the specific reason.
MeetJune accepts Visa, Amex, Mastercard, Discover and all credit cards that are accepted via PayPal. Be sure that you have entered all of your information correctly, that you activated your card and that your card has not expired.
If your card still does not work but you are sure you have entered all your details correctly, you may have to contact your bank or the card issuer. You may also try using an alternative method of payment.