Assuming you repeated comment correctly, which I believe you did. The phrase ...next time your brakes fail... What the idiot thinks you should wait until the fail completely? That sort of comment should earn that knucklehead a trip to customer service rehab.
It's exactly such comments that will set off an otherwise reasonable customer.
I also agree that the wear on rear brakes is VERY unusual. Next time you finish a stop and go city drive check the wheel temps front and back. IF the rear wheels are significantly hotter then something is dragging big time. That's the only way the kind of wear you are reporting could occur. (I say wheel temps because as you can imagine the brake rotors could give you some serious burns and if the brakes are dragging, the heat will be spreading to the wheels too.