I have to say I solved the problem myself, and I'm a proud S2 licensed person from now on
To make this topic not useless, I'll explain what was wrong: the security code of Visa Virtuon card is written not on the card itself, but on your contract with the bank (at least in where I come from).
So, the golden rule is don't lose the contracts. I'm glad I didn't
Those 4 digits I mentioned before have nothing to do with it
By the way, thank You again, Viktor, for your help and attention