Dollar, nickel and diming
 

Hired a car at Orlando Sanford through a European booking agency that offered the option of returning the vehicle full of gas.
Informed the agent that this would be the case and that I would require absolutely NO extras.None.Zilch.Nada
Unable to read the contract on the hand-held device before I signed it but was assured by the agent the $165 on the bill was in case I didn't return the vehicle full and in case of any damage.
Returned 10 days later to discover that not only had a pre-paid fuel amount been deducted from my card but also Roadsafe roadside assistance, something which was specifically omitted from my original rental agreement but magically appeared without mention to me on the Dollar agreement.
Blew a gasket at the airport and was given a receipt by the agent assuring me the full $165 would be credited to my account.
Of course it never was and after complaining to Dollar customer service was told the Roadsafe item would be refunded but not the pre-paid fuel amount event though the vehicle was returned full of gas.
It turned out the " refund " receipt was just a copy of the orignal one authorising the funds.
How can " reputable " companies such as Dollar get away with such fraudulent behaviour and is there an independent organisation where complaints such as mine can be considered ?

You can dispute the charge with your credit card provider. All the US rental car firms are known for attempting to run up their customers' bills with extra / unauthorized charges. They are particularly apt to try it on with foreign visitors.