Cannot download the full version of circle 2

I bought Circle 2 in December 2013. Have changed my machine since and trying to install the same on a new one. I have the activation code but there’s no option to register the trial version that I’ve now downloaded from the website, which wasn’t the case earlier. I cannot login into my account either using the old email address, the one I used to make the purchase from. How do I get access to the registered full version? I’m on the latest Mac OS. Thanks.