I am installing InDesign CS4 on a new computer. I originally had PageMaker 6.5, then purchased the InDesign CS4 upgrade. When I install InDesign CS4, it asks me to provide the serial number of the PageMaker 6.5, but when I do it does accept it. Last time I had this problem an Adobe support person showed me how to get to the "Upgrade Code Entry" screen. It provides me with the 123981 code and then tells me that an Adobe Customer Support person can provide me with a "Response Code" that I can then enter and finish the installation. I just need the response code from you.
That's not something we can provide on the forum, sorry. You'll need to contact customer service again.