While you have the Volt cut into two, you might as well stretch it into a 30-40 foot limo. Even just 1 section to add a row of seats would solve the seating and cargo space issue. It would clobber your EV range though.I could. It's been a while since I was in that business though.
BTW, you have a private message.
My vote goes to the charge port or a connector problem near the charge port. Though the time I had trouble charging, a moth kamikaze'd himself towards the light on the end of the J1772 just as I was plugging in. I had to scrape bug guts out of the plug and the port before it would charge. Don't worry, the power won't flow until the EVSE and car successfully negotiate the rate through the pilot wires. Go from easiest to hardest. Clean the pins in the plug and port first, then replace the port, then look deeper into the car.