You say it didn't work ?
What do you mean ? It didn't change anything ?
In that case, it means that you're not editing the correct email if nothing changes when you change it.
This is the products listing code:
<h1 style="color:#1c8faf !important;font-size:16px;font-weight:bold;border-bottom:1px solid #ddd;padding-top:10px;padding-bottom:10px;">
{TXT:SUMMARY_OF_YOUR_ORDER}
</h1>
<table class="w550" border="0" cellspacing="0" cellpadding="0" width="550" style="margin-top:10px;margin-bottom:10px;font-family: Arial, Helvetica, sans-serif;font-size:12px;line-height:18px;">
<tr>
<td style="border-bottom:1px solid #ddd;padding-bottom:3px;text-align:left;color:#1c8faf !important;font-size:12px;font-weight:bold;">{TXT:PRODUCT_NAME}</td>
<td style="border-bottom:1px solid #ddd;padding-bottom:3px;text-align:right;color:#1c8faf !important;font-size:12px;font-weight:bold;">{TXT:PRODUCT_PRICE}</td>
<td style="border-bottom:1px solid #ddd;padding-bottom:3px;text-align:right;color:#1c8faf !important;font-size:12px;font-weight:bold;">{TXT:PRODUCT_QUANTITY}</td>
<td style="border-bottom:1px solid #ddd;padding-bottom:3px;text-align:right;color:#1c8faf !important;font-size:12px;font-weight:bold;">{TXT:PRODUCT_TOTAL}</td>
</tr>
<!--{START:PRODUCT_LINE}-->
<tr>
<td style="border-bottom:1px solid #ddd;padding-bottom:3px;">
{LINEVAR:PRODUCT_IMG}
{LINEVAR:PRODUCT_NAME}<!--{IF:ORDER_PRODUCT_CODE}--> {LINEVAR:PRODUCT_CODE}<!--{ENDIF:ORDER_PRODUCT_CODE}-->
{LINEVAR:PRODUCT_DOWNLOAD}
{LINEVAR:PRODUCT_DETAILS}
</td>
<td style="border-bottom:1px solid #ddd;padding-bottom:3px;text-align:right">{LINEVAR:PRODUCT_PRICE}</td>
<td style="border-bottom:1px solid #ddd;padding-bottom:3px;text-align:right">{LINEVAR:PRODUCT_QUANTITY}</td>
<td style="border-bottom:1px solid #ddd;padding-bottom:3px;text-align:right">{LINEVAR:PRODUCT_TOTAL}</td>
</tr>
<!--{END:PRODUCT_LINE}-->
<!--{START:ORDER_FOOTER}-->
<tr>
<td colspan="3" style="text-align:right;color:#1c8faf !important;font-size:12px;font-weight:bold;">{LINEVAR:NAME}</td>
<td style="text-align:right">{LINEVAR:VALUE}</td>
</tr>
<!--{END:ORDER_FOOTER}-->
</table>
This is the code for the additional information:
<!--{IF:ORDER_SUMMARY}-->
<h1 style="color:#1c8faf !important;font-size:16px;font-weight:bold;border-bottom:1px solid #ddd;padding-top:10px;padding-bottom:10px;">
{TXT:ADDITIONAL_INFORMATION}
</h1>
<p style="border-bottom:1px solid #ddd;padding-bottom:10px;">
{VAR:ORDER_SUMMARY}
</p>
<!--{ENDIF:ORDER_SUMMARY}-->
simply switch one with the other in the code of the email.