How do I exchange CS5.5 Windows version for a Mac version?

I bought the downloadable online student version of Adobe Creative Suite 5.5 (windows version) over 2 years ago.  I just bought a Mac and would like to re-install CS but according to Adobe website, I need to exchange the windows version for mac version but since I don't have the most current version of CS (CS6?) I actually have to purchase an upgrade to CS6 first in order to exchange the windows version for mac. Does anyone know how to do this and how much it is going to cost?  I found instructions online that led me to a form that was a little vague and confusing so if anyone knows another way to go about doing this let me know!  Also, I don't think my membership allows me the privilege of actually speaking to someone in customer service.