RetroPie is not a sold product, in fact the license prohibits the sale of the RetroPie image - see here - not to mention the unlicensed ROMs you got with the image. We make RetroPie available as open source and it's free - this is outlined in the info message you get after updating RetroPie:

The RetroPie-Setup script and pre-made RetroPie SD card images are available to download for free from https://retropie.org.uk.
The pre-built RetroPie image includes software that has non commercial licences.Selling RetroPie images or including RetroPie with your commercial product is not allowed.
No copyrighted games are included with RetroPie.

Whoever sold you RetroPie/the setup you have is not affiliated with this site or the project and is a scammer. You should contact them and ask for support or your money back.