Lose Power Steering problems of the 2007 Ford Escape

Two years ago our Escape suddenly lost power steering due to faulty sensors. I took my vehicle to frontier Ford in santa clara, California, and they charged me $1200 to get it fixed. In the last 5 days, the power steering went out on me 3 different times -- all while driving -- causing me to have to turn-off the vehicle and then re-start it. It's my wife's Escape -- she weighs 106 lbs -- thankfully, I was driving the vehicle each time this has occured (I'm 220 lbs, and I cannot drive the vehicle w/o pwr steering. The first two times the pwr steering went out, I was backing the car out of the garage. Today it went out on me while I was stopped at a light, in heavy rush hour traffic. The warning light and bells came on saying "problem with steering" -- I turned the vehicle off, and then it would not re-start. It took several attempts to try and re-start -- it finally did re-start -- but only after infuriating a great number of people who were stuck in back of me during their morning commute.