This happened to me 6 months ago, and ive spent over £1500 trying to get it fixed. going into seat one more time on friday, should be good for another £500. Ive had a new pump, 2 new sensors, and 2 new steering racks! Its been hell
If i were you mate, i would only let Seat deal with your car from now on.
Im sure you will not have as much bad luck!