Hi
It is difficult to try to offer help when you don't give much information. What Mac do you have? Are you installing from Origin or from a disc? Is it just the base game or an expansion pack? When it gets stuck how long do you leave it?
If you want to obtain a refund then you would need to contact EA's customer services to see if they will refund your money.
In the meantime, you may wish to clear all TS3-related and Origin files off your Mac and try again. I read that Origin was not working for some people but that issues is supposed to be fixed now so it may be worth trying again.
Good luck
Caspin
