You sent collateral first to a Jr. Member with an open scam accusation. You can't really blame anyone for this. Use
an escrow or trade with someone who has a trade history.
Not blaming anyone. Just wanted to see if that scam accusation against him is true, it seems it is.
Luckily i sent him only 10% of collaterall (0.03 BTC value) instead all at once. Karma is a bitch @Developerx11 it will catch you sooner or later.