(mój login) your payment attempt was declined, which typically indicates that you input the wrong credit card information (please double-check it) or that your bank automatically rejected the transactions for some reason.
Please note that If you use your credit card through PayPal, the problem should be present as well, as though you used the card directly on our site.
Some banks automatically reject all international transactions (we're based in Europe). In such cases you should contact them and ask them to allow transactions with us. If you wish to do so, please use "GOG Limited" and "www.gog.com" as reference. You would have to confirm that you wish to make a purchase from us. This should only be required for the first transaction and the rest should go through normally.
Other possibilities are:
the card doesn't support online transactions (and can only be used in shop terminals and ATMs)
the card isn't activated or set up to allow online transactions
the card doesn't support international transactions at all (this is the case for many debit/prepaid/gift cards)
the card doesn't support transactions made when you're abroad (if that is the case)
(very rare) the card requires using the 3DSecure (Verified by Visa / Mastercard SecureCode) service, which isn't used on our service.
If contacting your bank doesn't help, there are two possible workarounds:
Use a different card (if possible)
Send funds to a PayPal account beforehand (under PayPal's My Account -> Add Funds) and then use that account to make a purchase on our site. PayPal typically only allows users to add funds directly from a bank account, rather than from a credit card. This will allow you to you avoid any credit card-related payment problems.