Hertz Car Rental - Panama City Northwest Florida Beaches International Airport - ECP - Florida - USA

I booked this car the morning I flew into ECP. The cost of taxis/shuttles was prohibitive - quotes of $70 - $100 to go ca. 24 miles to St. Andrews Yacht Club. I went on Priceline, bid $11, and with taxes, the amount came to $26.53. Showed up at the Hertz counter, and was told I needed 2 forms of photo ID, since I was using a debit card. Didn't have that, as I had only brought a debit card, driver's license and insurance card, instead of my entire wallet. The agent stalled for a while, then went ahead with the reservation. Got a Chevy Spark - very little car, which was fine for my purposes. Had the car less than 4 hours, drove it 53 miles total. Turned in my paperwork with mileage and fuel gauge indicated - fules gauge still showed "full". The dropbox on the Hertz counter says to turn all the paperwork in with the keys, and they will mail it back to you. Haven't received it yet, and this was 20 May 2015. On the 22nd, a charge of $60.57 appeared on my bank statement. When I called the main Hertz office, they indicated it was because I had returned the tank 3/8 full. When I pointed out that's impossible, having only driven 53 miles, the agent put me on hold, and came back to tell me she had reduced the fuel charge by half. That wasn't acceptable to me, and she told me to call the Panama City location. I have tried to call them, 8 times in one day. Two of those times, the phone was picked up and hung up. I called the mail Hertz line again, explained my situation, and the very nice representative sent an email to the location. She said I should be receiving a call or email from upper management within 24 hours. Nothing yet - no call, no email, and I still have $60 and change charged to me for driving 53 miles in a car that gets 39 miles to the gallon. I can't help what the gauge indicated - it said full - but if I'm to be charged anything, it should be for 1 1/3 gallon MAXIMUM. Silence from this location is not an option, and I'm less than impressed with how they are dealing with this matter.