How do you deal with stubborn clients while keeping a positive atmosphere

Hello,

I just upgraded my importer to replace all images with a single placeholder image, and from the 3 recent purchases, 3 of the clients complained about not getting the same result as the demo due to missing images.

A Notice in the product that images are not included is already added in the description

Now i can create an email template and send that everytime i get such emails, but i cant help but wonder, is there something im missing, or a better solution for this problem?