The reason internal and external keyboard not to work is because the complete Mac os is removed along with MacBook onboard firmware too which is in logic board. So no keys will work from turning on Mac laptops but will detect in windows os that is installed in MacBook. When I contacted Apple customercare is like I'm talking to people who have no knowledge.
The only solution you can do is remove the HDD or SSD from this MacBook and insert it to other same model working MacBook which has Mac os firmware that is not erased and install Mac os with your bootable disc or flashdrive that contains Mac os by going to option mode. Just try and check this if it works. And other way is connecting hard drive which has Mac os update or download the Mac os driver and check.