No money back when all is as it should be. The dragon did not trigger, because it did not attack. It ENTERED attacking. Thus is was attacking but never attacked. To attack with a creature means to DECLARE it as attacker during the declare attackers turn based action.

508.4. If a creature is put onto the battlefield attacking, its controller chooses which defending player,
planeswalker a defending player controls, or battle a defending player protects it’s attacking as it
enters the battlefield (unless the effect that put it onto the battlefield specifies what it’s attacking).
Similarly, if an effect states that a creature is attacking, its controller chooses which defending
player, planeswalker a defending player controls, or battle a defending player protects it’s attacking
(unless the effect has already specified). Such creatures are “attacking” but, for the purposes of
trigger events and effects, they never “attacked."

I want my money back