Working example: http://jsfiddle.net/Gajotres/uP9bn/
You can't use listview('refresh') on something that is not a listview:
$('#volunteersList').append('<tr><td>' + label.text() + '</td></tr>').listview('refresh');
I have removed it and now it works:
$('#volunteersList').append('<tr><td>' + label.text() + '</td></tr>');
Find out more in my other article: jQuery Mobile: Markup Enhancement of dynamically added content.