Google merchant items submission issues

I have about 10 products to upload, when trying to publish the product feed of our site on google merchant, I am receiving the following messages below: "Your data feed has been disapproved because some or all of your items are not complying with our Program Policies. " I have seriously checked with google's program policies, but I still can't find which policy I failed to follow. My web shop is using opencart, I am using a extension to directly create the feed, I would like to be able to do this myself eventually, so I need you to find where I failed to follow, and to be considered finished and successful the data feed must be accepted by Google Merchant Center! The products must be found in google shopping search results.