Hello! If there is somebody from Latvia, can you please tell me, how to pay for hi-res skins using SEB MasterCard? I always get error like "The bank didn't authorized transaction blah blah".

If the card is not blocked, it should be accepted. If payment attempts do not work, then 99% of the time it's because some card data field has not been filled in properly.
Please re-check the values you enter on the payment page and make sure they are correct (especially the security code, which is located on the back of your card). If in doubt you could ask me more, but I'd suggest mailing us instead of writing here.

Unfortunately I cannot say much more about it (because there's nothing more to say about it )

Everything but shipping address is correct, but I do not know in which format it must be.

Also, the card is not blocked, because I can check balance and withdraw cash at ATM's.

Have you tried to pay with paypal? For me it was the only way to buy a license. First i tried to pay with credit card, but all i got was "The bank didn't authorized transaction blah blah". When i payed with paypal, it was ok, as you can see.