Has gas stations charged you a service fee amount greater than what is posted?

I put gas in my truck this morning and as I was paying at the counter I stopped to read the "Fee Notice" near the pay point. It states that the merchant charges 35 cents for each separate transaction, yada yada. But when I look at my receipt they actually charge 45 cents? The lady at the counter doesn't seem to know why this is because she states that it's been that way since she started working there. Anyone know if these gas stations can add to your service fee charges this way?

that has never happened to me before and also there is something called paying tax to stuff you buy

kagome9874 is as usual, wrong. It's not tax, it's a convenience fee. It's set remotely by computers from the gas station headquarters, so the price will change before the attendent gets a notice to the price change. But anyways, it's just one of the ways the gas company gets around the laws and regulations to charge you more. It's completely legal, but a total scam none the less.