I opted for full-to-full fuel and refueled within 5 miles before returning the car, paying cash to fill up the tank. When returning, I provided the fuel receipt, and the inspection person used a scanner, issuing a slip indicating fuel level 3 out of 8 and a total of -181 USD. I found out after I returned home that they claimed I didn't fully refuel the tank, as it was only three-eighths full. Since it was my first time renting a car and my English isn't great, I asked if I didn't need to pay anything and if the money would be refunded to my credit card. The person said yes, so I didn't keep the receipt. In the end, I discovered that 181 USD had been charged to my credit card.