Accelerator Pedal Sensor problems of the 2009 Toyota Matrix

While driving on the highway on February 23, 2012, I lost acceleration with no warning whatsoever. No other problems were encountered at that time. I was able to get off the highway and have my car towed to the dealership. Their diagnosis was as follows: "connected scan tool and found code p0121 throttle pedal position sensor switch a circuit range performance, performed inspection and found internal malfunction in throttle body sensor, replaced throttle body, retested working normal at this time" I am in possession of the defective throttle body. On February 24, 2012, I called Toyota and reported my incident. They provided me with the case number 1202242199. According to Toyota, they haven't heard of this issue in the past, but to me it is unreasonable that the throttle body should fail so soon. While my car is nearly 4 years old with just over 74,000 miles, most of those miles are from driving constant highway speeds because I have a 60 mile round trip commute to work. On September 17, 2011, the throttle body was serviced to remove carbon build up.