Hertz Rent A Car Deceptive practices, poor attitude Atlanta, Georgia

I rented a car through Hertz for $84 for weekend out of Atlanta.  At the desk, was pressured to upgrade.  Was told the total for the weekend would be $115 if I upgrade, was told I would pay another $30 essentially.  Explicitly asked and was told it would be $115 instead of $84.  After I turned in the car, I noticed my card was charged for both the $84 and $115.  I called and the rep was nasty, said it my word against the sales counter and refused to put on a supervisor.  Multiple phone and e-mail requests for a manager to make contact have been ignored.  I have read the contract and it states the total charges would $115.  Nowhere in the contract does it state $115 + $84.  Hertz also has ignored my complaint through the Better Business Bureau.  I disputed the charges through my credit card. They report Hertz won't respond to their request either.  Deceptive company, be very cautious before agreeing to anything.   Have a poor customer service attitude towards consumers.