When you enter the criminal world, you leave the civilized world behind, and you play by the rules of the criminal world. This is what you accept as reality once you enter. There's no pitty, there's no goodwill and there's no empathy, even if you're an ethical criminal - you might get shot, killed, buried alive or otherwise be put out of commission for good. All it takes is that some other criminal you're doing a deal with have a bad day, and you say something that he don't like.
Now, binding up money with an unregulated third party online is always a risk. Make this third party a shady player in the grey market, and add the liability of you owing criminals in the real world money - and you have a pretty damn huge problem when this thrid party fails to honour their side of the agreement.
The real world criminals that you owe money will take no excuses. And you might end up dead. This was the risk you took when entering this world. And if you were naive about it, dismissed this being a possibility, or thought the risk was small and your greed was even bigger, then now is the time to face the consequences.
Like leaving the antelope herd on the African Savanna and running around on your own, this was your choice, and you're now prey. It's only a matter of time..
You could always try to run, you could always try to find a new territory, but you will always have the knowledge that somewhere out there, somebody is hunting you.
This is survival of the fittest, and these sheep market drug dealers just failed.