This experience is very interesting, although it is not a happy one. I'm curious though if you deposited that $ 100 that you didn't say.
Anyway, an ingenious way to fool people, but all of us, we have to start from the idea that nothing is free in this world and no one gives us anything without working. Whoever wants to do a 50/50 business chooses to do it with a friend of his, not with someone on the telegram.
The baseline, or, the majority of people in the world is Gullible, that's a reality we have to face. If they keep hearing about bitcoin but don't bother looking into it, and then someone offers them a effortless way to make it big with it, what they have heard is people becoming millionaires with it but don't know the mechanic behind it - they just think it's that easy. So they go ahead and get themselves in suboptimal situations. Looking it that way it's not so hard to believe how many people get scammed left and right. Not to say they aren't guilty at all but just giving some light on their thoughtprocess on the matter.