I put 40$ for my gas limit used 35 and couple cent...

I put 40$ for my gas limit used 35 and couple cents ,usually when your car gas is full it's stops and gas station charges for that amount 35. I didn't get my receipt ,which I should have .. and when I looked on my card transactions it charged me 40$ . Such a ripoff. This was the first time I used this place ,never comming here again.