7 Eleven Mobil Gas Station Scam, overcharging at the pump San Bernardino California

On more than one occasion I have pulled into this gas station under the false advertising as to the posted prices,  to learn after paying the pump was charging .10 more a gallon that I seen on the posted sign,  I know some stations charge more for credit sales or discount with additional purchase however,  this was a cash sale and there were no other prices or signs posted.   Also,  there were 3 employees inside standing around so the excuse of they were going to update or change would be bogus as I drove back by hours later and noticed  prices posted is still different  than what you are charged at the pump,  I'm sure others are being scammed,  who knows how many people are coming and going not catching this and they are benefiting from it, I'm thinking of actually going and holding a sign in front telling customers of their scam!