Let us know when you have a viable scam accusation then, with facts and proof and stuff. So far all we can see is just some speculation based on your assumption that Hhampuz was not authorized to move the funds. There is no plausible reason to think that way. He was entrusted with far larger amounts even in that same campaign. He can surely be trusted to handle the remaining 0.5 BTC the way he's supposed to, whether it needs to be returned to BestMixer, or held for a while, or converted to fiat, or if that's his compensation or perhaps half a dozen other possible reasons.

Embezzlement wouldn't be the first thought for a reasonable observer but for you it's the only thought. Something's seriously wrong with the way you're put together. If you directed this much effort into finding a job you could be doing much better than you did with the Livecoin signature.