it happened to me as well last year, it is blocked because you proibably didn't have enough money for the last payment maybe. Remember, if you want to buy lets say phantasia potion it is 7 euros yes but you need to have at least 8 on your card, not 7, something. Just don't try it again because every other attempt will block your card next 24 hours. So because i tried that one time like a billion times and it didn't work it was probhably blocked for like a month lol. So i e-mailed the support and they fixed my card in 2,3 days