Abs Brake Fail problems of the 2011 Toyota Prius

Break actuator is failing in my 2011 Toyota Prius. The car now has a unpredictable abs breaking system. Sometimes the breaks work and sometimes they quickly fail and a error light comes on. The light than goes out as if nothing happened and all is fine. This is a very dangerous problem that will lead to many accidents because the vehicle tells you its good to go, mean while the abs system is failing to stop the vehicle intermittently. I am scared because I dont know if the car will do this on a turn then lose control injuring myself and others.

While driving at a slow speed, the traction control, brake and abs failure lights came on. When I attempted to stop the vehicle, the brake pedal went to the floor without actuating the abs system. I was unable to stop the vehicle using the service brakes. Since I was traveling at a low speed, I was able to slow down and come to a full stop using the parking brake. Now the vehicle is parked and undriveable. I contacted my local Toyota dealer requesting service and was told that they did not have a brake master cylinder or hydraulic brake booster in stock. I checked a second dealer and they told me that you can only get the two units together and that they were on national back order with no eta. Since purchase, I have experienced the issue that many people are reporting where the brakes release over rough road surfaces and the vehicle feels as if its accelerating. If you release and reapply the brakes it would stop. Like others, I dismissed this as a peculiar dynamic of the vehicle, however I am now convinced that there is a serious design flaw in this braking system which requires a deeper investigation. I have been in the auto industry for over 30 years and I can attest that it is not normal to have a total loss of your braking system like this, especially in a well maintained vehicle that is relatively new and have low mileage. This vehicle is now parked and available for your inspection if needed.