Best of luck to you... Might not be a bad idea to hang around the gas station and see if any Irate people come in... You can talk to them and just maybe...

Usually The bad gas thing happens when the their tanks are being fill at the same time they are pumping or they were pumping at the bottom their tanks... water is heavier then oil so it stays at the bottom of their tank,when their tank gets filled it bring the water into the mix and gets pumped into your car...

If you got bad gas it is highly likely someone else did and two against one in a law suit is a home run...