Sorry to hear about your car mate, though I haven't surprised to hear that. I know this place for a long time as I live nearby. You are not the first one who complained about this kind of thing. They never remove any part and leave it as it is, they are replacing junk parts and no one will recognized the difference until for some time (like what happened to wiper in your case). These kinds of things happen at night time and guys who are working on this "nivasa" are responsible (with or without knowledge of the owners). One of my friends told me that he even contact these people when he want to have a recondition part.
This is not a secret anymore as most of the people know about this place. Why people going to this place to buy a vehicle? Have anyone noticed condition of those vehicle? As far as I know when people can’t sell a vehicle at all they go to this nivasa. So why should anyone want to go for a junk?