GM and other car makers list the
EPA estimated mileage figures...they don't just make them up themselves.
The BBB just didn't tell you what you wanted to hear.
" I also provided a copy of an email from the dealer representative that I purchased the vehicle from. In the email, she claims that this happened with a Chevy Equinox and General Motors purchased the vehicle back."
Who was this "dealer representative"...the cashier at the payment window?
This all sounds like buyer's remorse to me. See if the EPA will buy the car back....they ARE the ones providing the mpg information that the mfr. posts.