Trouble getting from "free" to "premium"

[ryolou]

I tried getting the premium offer for 7€ but when I fill in , correctly , all the blanks a message shows up and says that something is wrong with the card and it might not be at its best..?¿ And then it says that I should try a different payment method or try again later.
~My credit card has the required amount of money in , so I don't think that's the problem~

[FREIFY]

Which card are you using, maybe double check the numbers, since it can be sensitive?