Northrop Grumman interview questions

I was invited for testing by phone. When I pass the test (what happened about two-three times a year, depending on the actual needs of the company (the turn-over rate is really high), I was informed that "I am in" and I was given the date when I was supposed to show at work. Two days before the start date, I received another phone call and I was told that "The person I was supposed to replace changed his mind and there is no empty slot presently". They called me again in few months.