Itch.io takes significantly longer than two days to respond to support requests.
All game asset packs on itch.io are required to disclose if they used generative AI. If the game asset you are complaining about does not have this declaration or claims to be AI-free, you may have a decent fraud case and I recommend also contacting your payment provider if itch.io fails to respond in a timely fashion. If the game asset does declare that its contents are AI-generated, you are unlikely to receive a refund.
edit: based on the title, it looks like you bought a bundle by HoriHoriPixel. Their content is correctly declared as AI-generated. While I personally would not buy this and do not want to see stuff like it on itch.io, there is no fraud here.