Sorry to hear that, might have to talk to the itch community about that, as they handle payments and downloads
Did you look in your Junk folder for an email from itch.io <support@itch.io>
This contains a link to your downloads.
I should know, that is what happened to my update.
Log in to your itch.io account and go to https://pixelforest.itch.io/flowscape
You can download from that page.
You can log on to this message page, so you have an ID and password.
Click this link and your download button will be at the top.
https://pixelforest.itch.io/flowscape