Exactly bro. They always mention it in job sheet. Just talk to apple support one more time. If no hope, then proceed with contacting a lawyer to approach consumer court bro. This kind of incidents happen in rare case. It could be human error I think. But they have to take responsibility.
With or without warranty doesnt matter. You gave a working device and now its in dead condition. they should have returned in the same way it was.
So talk to a lawyer and proceed further. whether to get the device back from service center or not have to be decided based on their suggestion.