Non-working keys, missed timelines, and poor communication from seller. What should I do?

So I won’t put his name in the post, but here is our communication:

Picture speaks a thousand words, this is basically the whole story.

– I send him money for 3…

Non-working keys, missed timelines, and poor communication from seller. What should I do?

Source: [H]ardOCP – Non-working keys, missed timelines, and poor communication from seller. What should I do?