The Sims 3 Island Paradise Installation Issues

I recently purchased The Sims 3 Island Paradise (download version) on Amazon. To install it to my computer, I must use Origin. But, whenever I attempt to install it, it gets to about 40% completion then spontaneously restarts at about 14% completion. I've tried reinstalling Origin, disabling and reengaging my firewalls and antivirus programs, and I contacted Customer Support from Origin. It turned out my Sims 3 base game wasn't registered to my Origin account, so we registered it, and finished the call assuming that had been the problem. But, once again the download reached 40% and resumed at 14%. I cancelled the downloaded and restarted, hoping it might work, but it worked for a few minutes then gave me a pop-up saying "the download failed". I am getting frustrated at this point, since I really want to play my game, but nothing is working. Please help!!!

PS: I am running on The Sims 3 version 1.5.4.022001 and I have six other expansions installed.