Dear Bankole,
Thanks for your response.
Checking this with our platform team it seems there is a mod_sec rule in place to deny PHP script run from within /images folder.
I have checked to see if we can remove this rule but that is not possible. Are you able to get in touch with the theme developers to ask if thy can love the captcha script out of this folder? We tried to do this for you but this script seems to be attached to more than one folder which means moving it could break the site.
Kind regards,
Scott
Eco Web Hosting