Brakes Failed problems of the 2006 Subaru Tribeca

I was traveling at about 30 miles per hour on my way to work. Luckily had not entered the freeway yet. Approaching a stop and my brakes failed! the pedal was hard as a rock. I could not stop the vehicle as I was heading into crossing traffic. I ended up hitting a snow bank. I had the car towed to the dealership for repair. They replaced the brake booster and vacuum hoses. On may 11, 2017 I had my vehicle in for the 120,000 service check. Upon picking up my vehicle, I was heading home and noticed that the brake pedal was very mushy and my foot was all the way to the floor and the car was barely stopping. I took the vehicle back to the dealership and they have yet to contact me regarding what the problem is. I feel that Subaru should be responsible for this repair and should recall the vehicles for brake booster failure!!! I have seen many posts on the Subaru forums regarding this same issue. I could have been in a serious accident! please respond. To 262-957-4861.