Hertz

This is the third time I am writing a complaint without hearing back from the customer service dept. When I returned my car at Sky Harbor Airport in Phx 8/27 I had a full tank of gas. I filled the car up the night before & drove immediately the next morning to the airport. Of concern is the fact that my sisiter and her family had the exact same car which we both filled up at the same station the night before (same type of car as well) Rav4. I have done this countless times before since I had a house in the area for years. I usually use a different rental co. but chose Hertz this time for some reason. I was charged $26.31 for gas on a car that the gauge registered full when I dropped it off. When I called the next day the customer service rep asked for my gas receipt. I took pictures of the entire exterior of the car but never thought to take a picture of the gas gauge. Who would think they would have to prove they filled the car up & get a receipt. Outrageous! Is this the newest scam out there now?
I would appreciate a response!
Car pick up 8/22/19 sky harbour Airport
Robert Dean
Cofirmation #: J12906037E6