Its almost never the fault of the individual gas station. Its the age of computers. When you're not traveling, all of your charges are coming from the same town and for the amount that a car's tank can hold. If charges start appearing from cities and towns around the country or for large amounts, that isn't normal usage as far as the computer is concerned. It assumes that your card has been lost or stolen and not yet reported. On occasion, the individual station has a limit on the amount of gas you can pump because they aren't paying up on time. You can't fix that.
There's a phone number to call on the back of the cards. I've eliminated most of the problems by calling that phone number and telling them where and when I'm going to be traveling, by carrying both a Visa and a MasterCard, and stopping for gas when the tank is still half full. Usually, I need a break, anyway.
Also, its a good idea to keep the phone numbers of all your credit card companies in a different place than your wallet in case you really did lose your wallet.