Post your code if you can, could be an arming issue? Otherwise..
The power distribution for multiple esc's is sometimes a sensitive thing. Long power leads can have massive voltage spikes, plugging and unplugging batteries alone can be one of the riskiest parts.
I have had esc's die on unplug, especially disconnecting the battery when the system is pulling any decent current.
Sometimes if nothing is physical damaged in the chip you can reflash the ESC if the firmware is corrupted.
Sometimes there's just no bringing them back.
Have you tested the ESC off the quad alone to verify that it has failed?