Crossgrade purchase issue (Logic Express 7.0.0 to 7.2)

Hi there.
I'm trying to upgrade my Logic Express 7.0.0 to 7.2 for my Intel iMac and I'm having a spot of bother. I start here:

http://www.apple.com/uk/universal/crossgrade/

then I select the top link on the right for Logic Express which takes me here:

http://www.apple.com/uk/universal/crossgrade/terms/logic_crossgrade.html

then I dutifully fill out my address info and submit the details, which takes me here:

http://backend.media.euro.apple.com/apple/crossgrade_display.php?programme=logic express&lang=uk&formid=e8j9s3m1&whichaction=display

then (this is where the fun starts), the Buy Now button takes me here:

http://store.apple.com/Apple/WebObjects/ukBusiness?type=bizukPRO&qprm=67752&part Number=MA343

which dumps me to the front of the Apple biz store. Hmm. I've tried searching for the part number stated at the outset (MA343Z/A), no dice. I've spoken to the sales team who batted me around 3 departments before apologising there was nothing they could do.

Am I doing something wrong? Thanks in advance for any tips.

Pete