Having the old KORD installed is not required to get the discount. In fact, you MUST uninstall the old KORD because you can install the new one. As explained so many times, installation and activation are two entirely separate things.
If you uninstalled everything, including the Addon Manager, which is what you seem to have done, you must reinstall at least:
- GSX with the latest full installer
- KORD V2
Then, you can activate the old KORD if it's not already active, and then you'll be able to get a discount, if you press the "Buy on Web" button of the NEW KORD V2, after you are sure the OLD KORD is Active.