Ask your question here if you can’t find the answer in the FAQ.

1) When installing the patch, the folder is clearly specified. By the way, after installing the patch, you can run it again, and the installation will start again - is this normal?
2) Perhaps the developers forgot to include the disk-free installation feature in their patch, which is why this issue occurs.
3) The patch version is indeed from the developers.

Probably the simplest solution is to just ask for the disk back.