Thank you for providing the files.
It seems that you have not included the base CSS file for RadScheduler.
Please rename the existing Scheduler.css file in appointments.aspx_files to Scheduler.Telerik.css.
Then copy the base CSS file Scheduler.css (located in the Skins sub-directory of the RadControls for ASP.NET AJAX installation directory) to appointments.aspx_files.
Finally add another <link> element in the head section of your page, like this:
|<link rel="stylesheet" type="text/css" href="appointments.aspx_files/Scheduler.Telerik.css" />
|<link rel="stylesheet" type="text/css" href="appointments.aspx_files/Scheduler.css" />
I have attached both files to this message for your convenience.
the Telerik team