Access to Adobe Audition CS6 for download?

I need to access a full version of Adobe Audition CS6 for my new Mac.

Where can I download it?

I had it installed on my old mac, so I have all the codes and upgrade codes - but - can't find a link to download it. The only link I can find is to the 5.0.2 update - but it tells me this update is not for me because I don't have the full version installed. Note that this is a Macbook Air with no DVD / CDROM drive - so downloading is my only option. Would appreciated some help from an Adobe support person. I do not want to go to CC - it's too expensive for me (a great pity because I've been using it for over a decade). Thanks in advance. Kevin Nolan