[MAC] Why am I having trouble downloading, installing, or launching Island Paradise on Mac?

• Origin ID: theoriginaldyani
• Are you opted into the Origin Beta? NO
• OS X version (How to find your OS version): 10.8.4
• Processor, Memory and Graphics card information 

  Processor Name:Intel Core 2 Duo

    Processor Speed:3.06 GHz

  Graphics: ATI Radeon HD 4670

• Expansions you have/have active: Generations, paradise, late night, pets, seasons, university, world adventures. Bought and "downloaded" Ambitions most recently from Origin, or so I thought
• Any error message received: None
• A detailed description of what is occurring: I bought Ambitions most recently, and was downloading it all normal. I stepped away from my computer while it was finally installing, and when I came back a message said that the installer quit unexpectedly. Now, when I go to Origin, it says Ambitions is installed and I can click "play". But when I click play, the sims 3 launcher comes up and does not recognize that I have supposedly installed Ambitions.   I check my Sims 3 applications folder and the icon for Ambitions was not there, just the readme.txt for it. 
• A detailed description of any troubleshooting you have already attempted: I have tried deleting the readme.txt and reinstalling Origin, hoping that I can redownload and install Ambitions again, but no. I am extremely frustrated at this. I should be able to download a thousand files of the game if I purchased it, no matter if Origin thinks it's already installed or not. I could solve this problem on my own if I could simply redownload and reinstall the expansion pack that I have payed for! I was looking forward to playing this on my day off. I don't even care about troubleshooting, just give me the download for Ambitions again and I'll fix it myself! 

Ursula: Please try the trouble-shooting steps explained in the first post.