Am I correct in assumming that with this code:
<?php if((isset($_POST['cs_approved']) && $_POST['cs_approved'] =="1") && (isset($_POST['cs_completed']) && $_POST['cs_completed'] =="0")) { ?>
you are trying to send an email where the cs_approved box is checked and the cs_completed is unchecked?
If so, a checkbox only sends a value if it is checked. if it is not checked it does not have a value.
To send if the cs_approved box is checked and the cs_completed is unchecked use:
<?php if((isset($_POST['cs_approved']) && $_POST['cs_approved'] =="1")) { ?>