so I bought the game in the Us but then I went back home in Italy...
 

and now when I start the game it says "your telltale account doesn't have this game, would you like to go to the website and buy it?" and then even if I click to move on (after selecting no, or even if I select yes and then open the game again) it doesn't do anything and I have to exit the game via alt+tab and close it from the outside.

???

don't tell me I have to buy the game again

Which game are you referring to?