Unable to install on Mac

Please someone I beg for help.  EA customer service is ridiculous and totally worthless.  

I have a Mac laptop running OS X 10.8.2.  I have Sims and many expansion packs, up to PETS, and have been running fine.  I purchased the Seasons expansion and when I try to install I get a message saying Power PC apps are no longer supported.  I have a feeling there must be an incompatibility with my operating system and the app but not sure why this expansion would be different from the others.

The EA rep's only conclusion was that I had a disk that was only for PC and not Mac even after I sent a picture of both the case and disk where it clearly says WinMac.  I even took back the disk and replaced it with a new one in the hopes that maybe my disk was a PC disk and just marked wrong, but no help.

Since I have been going round and round with EA for a week with NO help, I REALLY hope someone out there can give me some answers.  Thank you so much!