Installed and activated, created a calendar, events, tried to create a page with the shortcode, in HTML mode, as per your instructions, but the shortcode appears instead.
Rechecked your instructions, which refer to a button; no button in my admin bar,
I use TinyMCE, so I checked the shortcode button, but the only one is [spiderfc][/spiderfc]. I tried carious combinations with that, supplying the calendar name and theme ID parameters in every possible syntax combination... in and out of brackets, with and without quote marks... no joy.
Any known plugin/theme conflicts (I use Suffusion, which is excellent, and very stable have used it on about 8 websites without problems).
As I work for a charity, we cannot afford to progress to the paid version only to find that I have to spend a lot of time troubleshooting that too, so, unless I can see the free version in action first, I am afraid I will just have to uninstall it.