DataTables row.add() not working Ajax Server side - php

Question

I'm working on adding a new row in my datatable on button click. Here's my code:
HTML:
<table id="datatable-batches" class="table table-striped table-bordered forex-datatable">
<thead>
<tr>
<th>Batch #</th>
<th>Qty</th>
<th>Date</th>
</tr>
</thead>
<tfoot>
<tr>
<th>Batch #</th>
<th>Qty</th>
<th>Date</th>
</tr>
</tfoot>
</table>
Script:
<script type="text/javascript">
var table;
$(document).ready(function() {
//datatables
var batches_table = $('#datatable-batches').DataTable({
"processing": true, //Feature control the processing indicator.
"serverSide": true, //Feature control DataTables' server-side processing mode.
"order": [], //Initial no order.
"ajax": {
"url": "<?php echo site_url('oss/admin/ajax_batches'); ?>",
"type": "POST",
data: {
'<?php echo $this->security->get_csrf_token_name(); ?>' : '<?php echo $this->security->get_csrf_hash(); ?>'
},
dataSrc: function ( json ) {
if(json.csrf_token !== undefined) $('meta[name=csrf_token]').attr("content", json.csrf_token);
return json.data;
}
}
});
$(function() {
$('#new-batch').on('click', function(){
$('#receiving-box').css('display', 'block');
batches_table.row.add( ["3", "5", "2017-06-24 08:55:41"] ).draw();
});
});
});
</script>
Both are in the same file. When I hit the button, only the 'draw' number is increased but the data is still the same.
I also copied and pasted the example table here to make sure row.add() is working. Here's the debugger data for additional info.
Any help is highly appreciated. Thanks!