Brake Electric Antilock problems of the 1999 Lincoln Navigator

I was driving up to a red light and was stopping and applied even brake pressure. The vehicle slowed but did not come to a stop. I had plenty of stopping room and the vehicle just slowly drove right into the stopped vehicles. I know how to use abs brakes and just pressed harder and harder but thje car did not stop.

Vehicle was at dealer to have tires rotated & steering aligned. Consumer picked vehicle up & was traveling home at 50mph and brakes went out. Vehicle couldn't be slowed down. Upon entering consumer's complex vehicle went over a speed bump & hit brick wall, to stop it. Dealer found that speed control cable was cut. Lincoln dealer hasn't contacted. Consumer back on the problem.