Sims - Get Famous pack purchased but no available to download

In what country are you? 

Ok, there seem to be some issues in other countries. Could you try starting Origin as administrator?

You can do so by right clicking Origin and choosing 'start as administrator'.

I preordered the game but it won’t download!!

it just keeps saying please try again later

any ideas?

Could you try this:

When a game won’t download

If your games won’t download, try downloading them in safe mode.

1. Launch the Origin client and log in to your account.
2. Click on your EA ID below your avatar.
3. Click on Application Settings, then click on Diagnostics.
4. Under Troubleshooting, toggle Safe mode downloading to On.
5. Restart Origin, then try downloading your game again.

Link: https://help.ea.com/en-us/help/origin/origin/my-game-downloaded-through-origin-but-will-not-install/

Try and see if your security software might be blocking the connection for Origin by turning it off to test.

If that doesn't work try clearing Origins cache files:
https://crinrict.com/blog/2014/09/delete-origin-cache-files.html