How do you download Riverview on the Sims 3?

When I tried to download Riverview it went through the procidure of downloading and then it didnt show up under towns when you make a new town in the game. then since it wasnt there i went back to the place i downloaded it from and i tried to download it again but it said that it was already downloaded. i looked under downloads on the game launcher but theres nothing there. WHAT DO I DO????? please help by giving s[ecific instructions cuz riverview looks REALLY cool!!!!!