There is a problem about payments done by cards. Visa Master Bank & Credit Cards. It will be available in a few weeks. So there is nothing to worry about.
You can still buy via NETELLER SKRILL ONLINE BANK TRANSFER.
If you wanna buy with cards there is another option.
You are going to this website of G2A : https://pay.g2a.com/
You create a g2a wallet then you add funds there with your card.
While you re doing that it needs to be €€€€ EUROS AND ONLY EUROS.
There is your money in G2A Wallet. You can login to our website and purchase by G2A Wallet Service.
There you go it is a bit longer way to purchase but if you want to use cards that is the only way right now.
I want to say this again this is a temporary situation. It will be fixed in a few weeks.