activation code does not work for upgrade from Elements 7to8

I have Cubase LE AI Elements 7 and purchased an upgrade to Cubase elements 8 but was unable to activate it with the activation code provided.

I connected my USB eLicenser and updated the software and also performed online synchronisation but it still didn’t work.
The only reason I wanted to upgrade to Cubase Elements 8 is that after I purchased expansion pack Pop Essentials for Groove Agent I found out it was not compatible with Cubase elements 7 and I require Cubase elements 8. I purchased the upgrade from Upgrade Now to Cubase Elements, Artist or Pro | Steinberg. Customer Number: 62562051

Very frustrating!