Fraudulent gas reimbursement charge - common practice?

I recently took a vacation with my wife and two kids to Florida to visit my in-laws and for the first time, booked a car rental through Turo thinking it would be a more convenient option for us. Everything went relatively fine until return.

The trip was booked from 3/1 to 3/6. I received the car with a 90% full gas tank and 380 miles of range. Upon return, I refilled at an Exxon Mobile not 5-10 minutes from the airport. I filled it to 100% and 415 miles of range - more than the host left me with at pickup.

Yesterday, I received an invoice from the host for a gas refill surcharge of $20+ plus a $10 extra fee. I explained the situation to him with a screenshot of the cc charge. I naively did not take photos of the odometer or gas meter, not realizing I would get scammed.

I disputed the charge and messaged the host this morning 3/8 at 8:25 am. He 'read' the message, ignored it, and pushed the charge through a day early from the 3/9 deadline Turo gave me to respond to the charge.

Is this common practice? The host had 100+ good reviews so I figured it was a safe bet but I'm 100% getting scammed and Turo customer service doesn't seem to be helping.