Worst gas, literally water. Went to waste so fast, had me thinking my car was messed up

Perla refuse to sell me gas because she do not have $30 change to give me. it was 3pm how could she not have $30 of change out of $100 bill that i am paying her. my tank is empty and i have 3 small kids sick in the car with me and her refusing to sell me gas even i have money to pay for is unacceptable. now i have to look for another gas station to put gas instead of saving me time so i can go to my kids doctor appointment right away... Perla from speedway express in Delano, CA