Recent front disc replacement now causing low speed ABS activation on drivers side. on 1999 Chevrolet 2500 Pickup

Recently had front disc replaced and rotors turned on 1999 K2500 crew cab. ABS activates on left front now at low speed and then brake fades and pulls right. this did not happen before the repair and happened first braking after leaving the shop. Am told ABS speed sensor is out and needs a $400 plus replacement. Repair shop says its cooincidental it happened the moment of their repair. Seems highly suspicious, since the vehicle was fine going in and problem occurred immediately coming out. Saw there was a recall on this back in 2005 (recall id#62686). looking for a recommended course of action. Thanks

Asked by for the 1999 Chevrolet 2500 Pickup
If there was a recall on this, then call your Chevy dealer and ask them about helping. They may be able to set you up at no cost by covering the recall. They can look up whether your truck was affected by looking it up by VIN.

As for the problem you're having with the shop--it is true that wheel speed sensors are easy to damage while doing brake or suspension work. If the shop isn't volunteering their help, it's going to hard to settle. Did they test drive the vehicle before returning it to you?
matte, They apparently did not. My wife called them the second stop from pulling out of their garage and told them it was not right and I called them later that night. we are follwoing up again today and will see where this lands. Thanks for the reply.
2 more answers
I am a mechanic and have been for over 15 years. I am a soldier so I usually don't have the time nor am home long enough to complete my own repairs like I would like to be able to. I had front rotors and pads replaced on my 2000 K1500 silverado and wen I first drove it afterwards I had the same abs activation at just under 10 mph. I replaced both front wheel speed/abs sensors and still have same problem. I'm thinking it had to be mechanical cause an electrical fault would trip the abs light. I'm still messing with it now as I write this.
@ Anonymous, were you able to figure any further information on this issue?