Got My tank filled with 50 Liter of Petrol of the very first time!
the vitz/yaris (any petrol model ) has a tank capacity of 11.1 gallons (US), which works out to be 42.01807litres so it would seems that once again you got caught out while not paying attention. WAKE UP!!
there isn't a chance that even .5 of a litre woudl be in the pipes. have you ever seen the size of the fuel pump, pipes etc,... i think they didn't reset the meter when they filled your car and you shoudl go back immediatly with the reciept and get a refund.
I hope you got the reciept (with your cars number on it and the amount of fuel put in) otherwise you have no proof and no case.