As most fuel retail outlets are franchise or small businesses, boycotting them for a day and buying your fuel on another day is counter productive to lowering fuel costs.
Government won't notice, excise and gst still collected.
Fuel supplier won't notice, you still bought fuel.
Small business paid staff for the day, power, lease, didn't sell as much chocolates or drinks that day (because they actually make more profit on these goods than petrol), needs to keep petrol price up next few days to cover the profit losses.
End result, fuel price stays higher, longer.
But I'm sure it seemed like a good idea...