This is the response I just received
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Your request (#Modern War Issue Report) has been closed. This means that the issue is being worked on now, or the issue is solved.
To review, comment and reopen the request, please respond to this e-mail.
S, Nov 30 15:59 (PST):
Hey Kim,
Thank you for contacting GREE Support.
Please restart the app a few times as if you completed the event you can find your rewards in your inventory.
Regards,
Stephen