I would be glad to give your money back, but it seems itch.io doesn't have functionality for this. Or maybe i can't find it, if there is one I'll send back your money right away. Or maybe you can make your bank get it back. Thats regarding money.
Now about the game itself. Would be helpful to know what version of the game you have, you can check it in the bottom-right corner on main menu screen. You might have the version before the fix, when it indeed crashed every 2 minutes and at that time only demo was available. If it is the case would be nice if you can test the newer version.
One more question for better understanding, what Windows OS (7, 8, 10, 11) do you have?
Sorry that you have to deal with it, hope we can sort this out.