$20/gal is too high for 15% fuel anyway but 15% is fine for your engine, $15 would be a more typical LHS price(depending upon brand). I'm kinda surprised they offered to tune it in the first place. My LHS's wouldn't even know how, they are train people. If that is your only LHS, don't burn the bridge behind you. You will need to go back to buy little things from time to time. Work your way thru this one and shift your major purchases away if you wish but don't shoot yourself in the foot seeking revenge. They will be able to survive without you easier than you will without them. Fact of life.[]

Now go fly and forget them for the day if you can.

Bruce