If a malfunction occurs, the fuel tank flap will have to be released manually ►Link.
The air in the tank will not be released. You will only be able to add a small amount of fuel.
You should stop fuelling the first time the filler nozzle automatically cuts off the fuel supply.
Drive to a qualified workshop without delay and have the fault rectified.
Note
The pressure in the fuel tank may be released audibly when you open the tank cap after manually releasing the fuel tank flap.