Although I contacted the support team at itch.io, as I expected, I don't think the refund will be successful. I just consider myself unlucky.
I want to say that he deleted the game but is still selling it. Isn't that a scam? After purchasing his game, I found that the files didn't exist. I commented on his new video on YouTube, saying that I bought your game but it was deleted, and he saw my comment and then deleted it, like a beast.
I fell into a trap; I'll take it as a lesson.