cant upgrade harmony advanced 17 to premium 20

i have bought a permanent licence upgrade from harmony advanced 17 to harmony premium 20 which i bought via the toon boom website but every time i enter the activate upgrade licence key i get an error message saying to contact support with the error code but doesnt provide an error code.

ive tried adding exceptions to my fire wall and returning the licence for harmony 17 as it suggested but its had no effect and i tried logging in via the licence wizard but get the following message “unable to sign in to your toon boom account. there was an error recieving the licence server. error downloading https://***********/server.php - server replied: forbidden. (202)”