Fuel Injection Rail problems of the 2012 Volkswagen Jetta

First compliant number-10442730 I am reporting yet another occurrence with this car. I have had this car at the dealer several times for the same issue. The dealer fixed a check valve because the fuel rail pressure was too low. Approx. 1600 miles after it was fixed the car started to do the exact same thing shuttering and stalling. The car is now back at the dealership and they are telling me that it is the fuel that we are using in my car. They took a fuel sample and also drove the car 300 miles and can't find anything wrong with it. I do not want to drive this car any longer for fear of being in a wreck. The car has stalled on my 3 times in the past month. Vw doesn't seem to think this is a big deal I have had this car for less than 6 months and the car has been in the shop several times I am paying for my car to sit in the shop! I want my money back. I will not know anything about there fuel sample test for three weeks.