Upgrading to mac appstore version

I bought MN3 via website. I did not noticed the two licence warning. Now i want to use MN3 on 3 macs. Mac app store version gives unlimited install. So i want to cancel my purchase and want refund to buy MN3 again from the Mac App Store. Is this possible?

Please contact sevice@marginnote.com regarding this issue.

Regards,
MarginNote
Support Team