2006 Chevrolet Trailblazer stability control problems

Since getting my car about 4 mos ago, the stabilitrak service light & indicator lights would come on, and it put the brake on by its self, the first time it did this, it scared me because I was going about 40 MPH and all of a sudden the brake almost stopped me, it has done this 2 or 3 times a week since, I talked to the chevy service dept., and they said it was safe to drive as long as I was careful, until I could get it checked out, I didn't have $80 an hr., to do that.

While driving at about 60MPH my ABS light came on an my car started jerking as the anti lock brakes kicked in. I let up off the gas but as soon as I applied the gas it continued, I then pulled over to turn the engine off I let it sit for about 5 min an started it back up an it was fine. This has happened several times over, an usually when I am going at a higher rate of speed. I would say it has happened at least 10x in the past year.