I worked in the oil industry for years, so here's the deal. Name brand stations get the best gas from the refinery, ie, Chevron refinery gives their best gas to Chevron stations. The lower end of the QA scale is sold in bulk, and that's where Raceway and all independent stations get their gas. If you are not going to get the 100% (which still isn't over 95%), then buy from name brand stations before you stabilize your fuel.

Secondly, stations won't refund more than the price of their gas, same as oil change places won't refund more than their oil. The legal argument is that once you drive off their lot they have non way to determine if you adulterated (like that word?) their oil or gas and so claim they are not responsible.

Sorry you had that trouble. I had to replace fuel filters and plugs and suck all the gas out of my tracker tank last year for the same reason. I even tried mixing in a little bit of alcohol but there was too much moisture in the fuel. Now I only buy 100% or from the local Chevron station.