Hi!
...no matter you have or not , you are refueled paying by fuel card or CC or even cash (Austria)
It probably depends on circumstances and who issues the fuel release, but in most cases we don't pay anything directly (carnet, CC or cash) when we have a fuel release. And even where we still have to pay for the fuel, the fuel release guarantees a fixed price. And I don't remember ever having to pay for fuel in cash, not even in Austria,,,