Europcar Stansted Airport, UK I made reservations through booking.com (although it looked like I was dealing with Europcar directly) and paid before pick up. The car I had reserved (and paid for already) was not available so they offered me a slightly bigger car for a minimal surplus, which I accepted. come to find out Europcar charged me again the full amount + the surplus of the "upgrade". I filed a complained with AMEX who were useless handling this despite having all the documentation I provided. My Advise: STAY CLEAR FROM EUROPCAR and BOOKING.COM. As far as I am concerned they work together and scam people in paying double. white collar criminals in the likes of the Liberian maffia.