Probably won't go anywhere, but try calling the local police and file a stolen property report. They acknowledged having his card, so they can't deny they had it. Not returning it and/or really telling him what happened to it is not really any different than if they stole it and then denied doing so to him. This BS of requiring someone sign a NDA and giving them vouchers instead of returning their item, or the money they deserve, is to me tantamount to outright theft. The NDA requirement is akin to a form of blackmail as well.
And the NDA requirement keeps all the other people this has happened to before from ever getting together and starting a class action lawsuit against the perpetrator. And we all know that if it were possible, there's at least a few attorneys that would gladly take such a case and go looking for more parties to join such a lawsuit for the eventual payday.
