Great at start poor at drop off

Routes not on main car rental location where most other car rentals are from airport so you need wait for their shuttle to go get you after you call that takes kinda long time to arrive...was like 30 minutes. Process of getting car was fast , got car I wanted to get in good shape, staff was helpfull with finding damages on car so they dont try to trick you. When I was driving piece of plastic on doors fell off, I didnt do anything to damage car was clearly manufacturer thing , googled piece of plastic was about 30 USD (new) but when I was dropping off car I had to pay 500 USD ,even tho I paid 500 USD already at beggining and gonna get rest back after repair for damages I didnt cause or couldnt prevent. Hope repair wont be overpriced becouse I know you just clean it and put there piece of plastic ,I know becouse I work in Škoda and I know how those being put on (we use screws tho so this cant happen , here was just glue).