Assuming that the OP's asserations are fact, filing a law suit would be difficult. Most attorneys would cnot handle such a "small" case. Those that would would provbaly require a substabtial retainer, like $5000, and ne charging like $200.hr. It could cost way more in attorneys fees than the amount that was lost.
As far as a class action lawsuit, 5 other victims would have to be located and be willing to be named as plaintiffs in the class action. But, AV123 is a small potatoes company - no deep pockets. So, I doubt any attorney would want to take it on.
In addition to alternatives to a lawsuit that have already been posted, written complaints filed with the FCC (which has jurisdiction over Internet) and the FCC (which has indirect jurisdiction over Internet sales) might (just might) do some good. I don't think the FBI would even want to hear about this.
Mike