Cubase AI5 - New eLicence Number


I installed a version of Cubase AI5 on my Mac in December 2013 and activated and registered the software with Steinberg at that time. I have the original activation code for the software and the original eLicence number saved and recorded.

My Mac was lost shortly afterwards and I have just recently recovered it. I am trying to use Cubase again but the application tells me that it needs to be reactivated. I have been trying to use the Steinberg website via my account to reactivate the software but I cannot get a new eLicence number from the eLicence control centre. When I enter the original activation code I get an error saying that the code has already been used. I have followed the instructions on reactivation in this article but it does not resolve the issue.

Any help is appreciated.