Engine Stall problems of the 2013 Audi A8

Driving car from provo, ut to California, approx 250 miles into the trip noticed the epc light on, I pulled off the freeway to check the engine and it stalled. I was able to restart vehicle and drive it to las vegas it ran fine at freeway speeds. When I got off the exit the car stalled and engine quit while I was rolling down the offramp. I came to a complete stop in the center lane of a three lane exit, could not get pull out of traffic because had cars in both lanes beside me. When the light turned green I got the started (using 3/4 throttle)but not until the light had cycled to yellow, car horns honking people yelling, I put the car into drive, shot across the intersection and rolled into an empty employee parking lot behind the rio. After several attempts go no go I made it to an overfull parking area and the next morning had the car towed to las vegas Audi. I continued my trip to CA. After renting a vehicle in lv. The next day their service department called and told me that one of my turbos had failed and that it was recommended that I replace both. Quoted 13,800 to fix the car. I felt trapped because my car was 400 miles from home and I needed it fixed. After talking to some independent shops I realized that price was in the normal price range. What I am most disappointed with is that Audi had issued a TSB on this engine explaining that the check valve and oil screen could get clogged and starve the turbos of lubrication. I was also scared when I broke downwhen I exited the freeway. I could have very easily got in a wreck because I had to keep the throttle so high so the engine wouldn't die. It was a dangerous several minutes for me and luckily I was in a area that I could get to a vacant parking lot with crossing too much traffic. My car had 67065 miles on it when I had it towed to the dealership.