In your FTP program ... if you click right on a file that you have highlighted you should have options for changing the permissions or chmod ...

When first installing Zen Cart, you need to have the two files:

/includes/configure.php

/admin/includes/configure.php

The easiest way to do this is to rename the existing files in those directory called:

dist-configure.php

to the new name:

configure.php

and then set the permissions to 777

This is much faster than waiting on your hosting site's tech support and you should really learn to manage your files yourself for ease of use of your shop ...