general problems of the 2003 Chevrolet Suburban

I'm having this problem now, I went to the dealer, and they want $280 just to look at it. I have sent it to another dealer and they have had the car for two days, but they cant find the problem. They even asked me to take the Suburban home, but one block it happened again. Im so fustrated, and I spent so much on taxi going back an fourth. And no one knows the problem. I was driving down the road and it just dies. When I pulled off I put it in park and started again, I was able to go one more mile and bam it did it again. Why cant anyone figure it out? why arent there any recalls? I lost all control of the vehicle because the engine died. What does it take to get someones attention? when the engine cut off at 69mph I pressed the brake which made it harder and harder to control the vehicle. There are no error codes or anything to describe the issue. I'm afraid to drive the car, for fear that I might slam into someone else. While I was driving, there was no detection of misfire or anything, it just died.