FYI:
The Omerta from the giveaway was the 4 DLC version, not the Gold version. The 4 DLC version has a game breaking bug. You can't finish the campaign. Kalypso has a fix for it since December last year. They have updated the Steam version, not the GOG.com version.
The Japanese Incentive DLC for this version works fine. That campaign can be finished. The JI DLC is part of the flash sales.
There's a
thread for people who missed the freebies. You can try your luck there.
I grabbed 1 free copy of Omerta, but already sent it to someone.