There could be several reasons for this…
The SA Activation does not work on a WordPress Multisite – I have been informed of this recently. Having never setup a WP Multisite before this is not something I been able to test.
The SA Activation does not work if you are installing onto ‘localhost’ – it needs to be on a site with an actual domain address to activate.
So if you have either of the above situations, then request a refund – I have no problems with issuing a refund at any point.
Sometimes your web host may have a firewall that may be blocking communication between your website and the license server (which is edgewebpages.com). So you may have to contact your web hosting company about this.
Also if you have a security plugin installed on your WordPress site, try disabling it for activation.