control the way corporations raise gasoline prices as they please every time before hollydays

Oil corporations claim they have to raise prices because world oil prices or problems in refineries, when that happen, they rise prices since first day, even do the gas they are selling, it was payed at lower price. And after the problem in the refinery is fixed, they low the prices very slow, sometimes pennyes at the time.
The profits they get this way is huge per day, is time and for ones goverment protect citizens against unfair rich companies procedures.