Change meta tags on my zen cart webstie.

This is probably and easy project for someone with the knowledge! I have defined meta tags for my products/categories and they are not showing when viewing 'page source'. The meta tags that are showing are the ones which are for my homepage. I am looking for someone to fix my site so that the defined meta tags show for each individual product and category (and do not show the meta tags which are meant for the homepage only). It would be useful if you have experience working with zen cart. Thank you.