@mistfirefly If even the default stuff (eg email) isn't getting through and the original site has customised fields in it, then not only will the template file have been changed but probably also the core file that does the sending. Switching templates won't affect that.
The core file that has probably been modified is includes/modules/pages/contact_us/header_php.php
Have a look at that and compare it to an unmodified one to see what changes were made by your predecessor.
Regards
David