Booking.com Price Mismatch Leads to Avis Overcharge

I made a car rental reservation with Avis through Booking.com for December 27, 2025, from the Edinburgh Haymarket branch. At the time of booking, a specific total price was shown and confirmed. However, after the rental was completed, I was charged an additional $324.48, which I do not consider justified. According to the information sent to me by Booking.com, Avis charged £185.06 (+ VAT) for fuel, £70.57 (+ VAT) as a city supplement, and £15 (+ VAT) for a late return. I returned the car with a full tank, so the fuel charge in particular makes no sense. The explanations provided through Booking.com were neither convincing nor reasonable and failed to clearly justify these additional charges. I contacted Booking.com customer service, and the issue was escalated to their customer relations team, but instead of resolving the matter, they attempted to close the case without properly clarifying or correcting the charges. My concerns regarding the unjustified extra fees and the inconsistency with the original Booking.com price were not adequately addressed. I am therefore requesting a full refund of the unjustified $324.48 charge, along with a clear written explanation of each item charged—fuel, city supplement, and late return—supported by proper justification. I expect this matter to be reviewed again and the overcharged amount to be refunded to my original payment method.