I have been back to support. Afterr getting them to acknowledge that CS5.5 did indeed have flash Builder 4.5 Premium bundled with it, they said that I was ineligible as it was not a 'point' product. I asked what a point product was and I was told I was being moved up to another support queue, but in fact I was just pushed sideways before being released back into a disgruntled community.
Now I am the one who is fully activated. I will not stop until someone at Adobe can tell me why I am ineligible for a part upgrade release [4.6 to 4.7] when I have a full product serial number for 4.5.
Does this mean that when any product is part of a CS studio bundle, that upgrades can be made ineligible because it is not a 'point' product? What next? Photoshop, InDesign?
I just think that the whole Flex, Flashbuilder marketing bungle's legacy is raising its ugly face in the form of incompetent and short sighted licensing and upgrade management.
So what is the answer?
@Neil: I apologize for the inaccurate information you've been given by support - Creative Suite 5.5 editions that included Fb 4.5 are indeed elgible for a complimentary Fb 4.7 license. Please fill out the request form at http://www.adobe.com/go/fb47_serialkey and if you have any difficulty, feel free to contact me directly via scastle at adobe.com.
Many thanks Scott. Resolved thanks to you!