Hi,
I don't see why it wouldn't work. Maybe some wrong permissions on the folders ?
Anyways, you can do install a manual installation:
- extract the install zip on your local computer
- you'll get two folders: css and images
- upload the content of the images folder in media/com_hikashop/images/ (via FTP for example)
- upload the content of the css folder in media/com_hikashop/css/ (via FTP for example)
- you ill now see the styles in the style setting of the Display tab of the HikaShop configuration