I found what was going wrong. You were absolutely right about the file that I need to edit. I was also doing it the right way but I decided to enter the function call into the developer tools search just to see if it was being called anywhere else. And of course...it was...so I commented it out in this file as well:

/includes/modules/product_listing.php

In combination with the file you recommended...I got the results I needed.
Thank You...I couldn't have done it without the your help.