Start playing music(or talk radio) back to them.
Bingo. Retaliate with whatever music will drive the customers away, at a higher decibel level than the gas station can put out. If there are no ordinances to stop the gas station, then there are no ordinances to prevent retaliation, and the dispute must be settled by the law of the jungle.
When I lived in the city we had some dindu nuffins move into the neighborhood. Crap music blaring at all hours. I got together with a few neighbors and set up a stream web channel for music and we just out blasted them from all sides with the same song over and over.
Melanie, Brand new roller skates.
They moved out in less than a week.
I’m out in the country now.