You are using version 1.7.8 which is quite an old version.
I do not have this version, but I suspect there is changes in woocommerce template hooks that results in this duplication. In my localhost setup, everything works properly.
Please kindly backup your current theme via FTP into your computer, just in case you need to revert back. Keep it safe on your computer.
Then update to latest version 2.0.1 which can be downloaded from your account.
After that, Please following this link to update 2 woocommerce templates in version 2.0.1 https://theme4press.com/support/topic/woocommerce-update-causing-issues-with-evolve-plus-templates/#post-20037
After you are done, Please clear your browser cache and revisit your website and test out your cart.
Looking forward to your reply.