Brake Sensor problems of the 2001 Chevrolet Astro

I have a 2001 Astro awd that was taken to meineke brake care center where the brake system was analyzed. The front driver (abs) wheel sensor needed replaced. Note prior to having this done the (abs) light came on therefore I knew that something was wrong because at a very slow stop the brake would release itself and would allow the vehicle to continue to move. After meineke analyzed the problem I had the brake sensor replaced, and the (abs) light went off and the brakes seemed to be working normal again. However just one week ago I was driving and came to a very slow stop, mind you the light (abs) is off and the vehicle would not stop and the brakes released all the way causing me to run into a fence. However, luckily no on was hurt or property damaged caused but without warning this could have been much more serious traveling behind another vehicle or large truck. The brakes has once again been analyzed for problems and the sensor that was replaced shows no issues. Can this possibly be a manufacturing issue that no one has reported? please advise with any information regarding this matter, it would be much appreciated.

Abs not stopping the vehicle at a slow rate of speed. Vehicle is still moving but the abs sensor thinks the wheels have stopped their for not stopping the vehicle when the brakes are applied. The chevy silverado's were recalled for this problem but chevy has not recalled this van which has the same braking system as the silverado. It has almost caused several accidents with our van.

The abs on my 2001 chev Astro are faulty, similar to the investigation on the pickups and suvs. At slow speeds, like in parking lots or at stop signs, the abs activates, the pedal becomes too hard to push, and I cannot stop at all. This happens even on dry roads. The repair is over $1000 with aftermarket parts and over $2000 with gm original parts. I disconnected the front abs sensors.