Ohno! That behaviour on the behalf of the developers is absolutely horrendous!They ought to give you a full refund!
(Also, not sure why you thought version 0.5 was the full game.)
Often, with Itch games, they give a large portion of the story, but some plot points, quests, or otherwise general features are left out, not "Here's the first few lines of dialogue, please give money"
You are aware that no one is making you pay, right? You can play what's here for $0.
