AutoNation Subaru Arapahoe

My 2011 outback was in for service every 2 weeks for 10 weeks and would develop another problem within 2 weeks of being repaired. The last time I took it in it had to be towed and couldn't even be put in neutral to be loaded onto the truck, the driver towed it on and bounced it off. After that repair I drove it to Phoenix where the problems started all over again. A local garage there determined it was the transmission valve body and replaced it. In doing my research 2011 subaru's are known for transmission problems around 100,000 miles. Why didn't the Autonation service department pick up on this? I had been the sole owner of this car and had taken it there for all of my servicing except for oil changes. I recently bought another subaru because I like the car but I will not take it to that dealer for servicing. I think they are too big with inexperienced mechanics. I expressed my complaints in a letter to the manager and he discussed them with me then tossed my letter in his wastebasket while I sat there. Obviously I still have the letter on my computer. The other issue with this service department is that you have to wait when you drop your car off for the person you made your appointment with even if they are busy and three other employees are standing around talking.