Very standard, not bad

Overall service was good, and the staff were very friendly. I originally chose an X-Trail but got a Ford KUGA instead (same price). The car was very new, with less than 7000 km. The return process was quick. After parking the car in the rental company's lot, the staff checked if the fuel tank was full and briefly inspected the car's exterior. Everything was fine But a few days later, I noticed a charge of AUD 31.75 for fuel on my credit card. I had refueled the car at the BP station next to the airport right before returning it, within an hour. Not sure what the reason was, but I don't want to pursue it further.

Like: Efficient staff, car in great condition and the holiday was made very pleasant with a car driving in Melbourne and surrounding areas.
Dislike: Wrong billing? I made a reservation for a Toyota Rav 4 for the period between 26 to 29 Aug 18. The reference number was 63103417 and confirmation number was 38357487SGD. The quote was AUD 303.72. I made a payment of AUD 60 as a deposit, and the amount due at pick up at the airport was AUD 243.72. At the airport, I was asked if I wanted an upgrade to a Toyota Kleuger which came with a GPS at approximately AUD 60. I agreed, and the final bill came up to be AUD 359.39 and I was charged this amount on my credit card. Shouldn't I be paying AUD 299.39, having considered that I already paid AUD 60 as a deposit? The bill number issued by Budget upon return of car was 317692550 and the reservation number was 38357487-SG-OH.