It took me a while to figure out why one of my cards would work at a card-only gas station and one would not. If your credit card requires a signature it will not work. The gas pumps require a pin, and these don't have one. You can use a card that has a pin. In my case my credit card would not work, but my ATM/debit card would. I found the same issue in some ticket dispensers (such as for trains or busses).

Many gas stations are card-only on weekends. Be sure to have a card with a chip and a pin code.