"Misc charges" added after return
 

I booked a rental for a full day from Avis in Hungary. I returned the car to the location after hours (was told this was okay) and parked it in their garage, dropped the keys in the after hours drop box.

When I got the final rental agreement a few days later, there was a "Misc charges" section for 400.20EUR and 9.50EUR (The whole rental cost before this was 89EUR). I am just trying to figure out what "misc charges" were incurred during my rental, because I returned the car with a full tank, no damage, etc. I called the Avis customer service number and despite going through the phone tree and selecting the option for assistance with an international rental, they said they couldn't view the RA since it was for a rental outside the US. I am normally a National renter so pretty new to Avis. Is there any way to understand what the charges are for? Is there any way to escalate the issue within Avis?