Norton Antivirus 11 end-of-support-life question

I have Norton Antivirus 11.1.3 and my subscription expires on 04/11/2015, so I purchased a renewal from within the product itself. The renewal code is not recognized, and I subsequently discovered that support is being discontinued for my platform (32-bit Intel Core solo Mac) effective 11/12/2015 or the end date of my subscription, whichever is earlier.

Since I paid for the subscription, how can I extend the ability to download updates until the 11/12/2015 end-of-life date? Antivirus protection is particularly important on computers that are incapable of running the latest and greatest OS version, and one of the things I really liked about Norton/Symantec is that you continued to support Mac OS 10.4.11–10.6.8 after other vendors discontinued support.  I would hate to have to go as a customer smiley