Hi,
I am sorry to hear of the trouble you're having. I am surprised that Customer Support directed you here to the norton Community to get this solved. This is basically a user to user support forum and we don't have access to your Norton account details. Symantec employees have their name in red.
I will bring this to the attention of a Symantec employee to see if they can look in to it for you.
In the mean time, can you check that you are entering the Product Key correctly. From memory, the NU14 Product Key is Case sensitive, so you need to use capital letters.