Aeria took over S4 in 2014. Back then you had to migrate your account to Aeria Games.
In case you did not migrate the account you can no longer use it. Moreover, account migration is no longer possible because they don't have the data anymore.
So I guess the only way for you to play S4 is creating a new account.
Ye, i guess they have blocked s4 in my country before it so ye i have missed it