Otto von Bismarck once said:
"Do not rely on an agreement signed by the Russians, it is not worth the paper it is written on."
And here they didn't even signed anything.
So just learn your lesson (again) and think twice before dealing with those liars dirty scum in ANY kind of field. Civilized rules and ethics simply do not apply to the Russians. All their neighbours are well aware of that rule written with their own blood through history. So it's time for the rest of the world to be aware as well.