Ai6 Ai7 Download help

Hi all on the forum,
I have had a look through posts for answer to my question but alas nothing pops out at me.
I have just bought a Yamaha N12 desk, not used but opened and original Ai4 disk corrupt. Now that Ai4 is getting on I would like to try Cubase Ai6 or Ai7, I have not had any use of Cubase in the past as I started using cakewalk sonar when I got into DAW in my home studio.
I know Ai6 can be downloaded from main site but as I don’t have activation code or eLicence it is not possible to get.

I know I can download 30 day trial of Cubase 7 but due to my work commitments I would not benefit from this trial, I will upgrade to full version of program when I get a chance to learn it but I would like the Ai version first to get used to program and my new desk.

Any help much appreciated.

Have to say that the forum has been as much help as Steinberg help desk.
No advice from either :frowning: