maybe it isnt just /ad bug, i am afraid /fillup got it too,
when i do fillup at a GS, then the commands keeps going, as long as i am at GS i will lose money and get fuel,
its auto flooding then, and it goes on all the time,
after you left GS you will still receive:
you cant do that here, or whatever it says
it really sucks anyway,
and your passenger will have to pay it all the time too, i did it as driver, and the fuel was going up, even when i left the car it had gone up, the passenger had the flooding too, even when he didnt do it