“Bad gas” is often an excuse used by incompetent repair techs or sometimes by those looking for a convenient excuse to do unnecessary repairs.
You may or may not have gotten bad gas from Bolla Mart Sunoco. The trouble now is that it will be difficult to prove.
Joseph Meehan and ZombieWoof ask questions that will need to be answered.
In addition to what they asked, how do you prove that the sample your mechanic gave you actually came from your car and came from Bolla Mart Sunoco? Unless you find others who bought bad gas from there as well or you can get current samples of bad gas, this can easily grow into a long drawn-out “he said, she said” battle.