Steering Is Tight problems of the 2012 Toyota RAV4

I drove vehicle in the morning, no indications of any steering problems. During my drive in the late afternoon, the power steering assist stopped working. I was stopped at a left turn lane and heard a faint "click" sound from below the steering wheel area at around knee level. This sound was not that of a "turn signal switch" click, it was just a "click". The engine stayed running, the eps warning light came on, the steering wheel was very hard to turn (I have carpel tunnel in my right hand), with assistance from my passenger we were able to complete the turn. We drove vehicle home without power steering and parked it. My brother-in-law came that evening to inspect for failure. Vehicle started up and power steering worked without problems. Since no eps warning light came on, he volunteered to take vehicle home to test drive until problem recurred. The dealer told him to drive the vehicle to them to have problem evaluated. He has put 500 miles on the odometer so far and problem has not recurred. He said the dealer will just give me the run around if no "hard code" is set and condition of no" power assist" is present. I am afraid of driving this vehicle now because of this problem.