Hi Mayorofseremban,
To be more specific: yesterday I've had the same problem. My iCloud login was stolen and my devices were put in lost mode. I gained control over my iPhone by changing the iCloud password. My iPad needed a factory reset because it kept asking for a passcode that wasn't set up by me. This was also a relatively quick fix and thanks to the iCloud backup my iPad was back to normal pretty soon.
When I've opened my Macbook Pro the locked screen was shown, asking me for a 6-digit code. There was also a message asking me for contacting applehelp@caramail.com. Off course I didn't contact that person.
Searching on the internet for similar problems (there can be found a lot!) I ran into this topic and thought by myself that it doesn't hurt to try.
At that moment my Mac was connected to the internet by Wifi. I pulled out the power plug, left my screen open and just waited untill the battery was completely dead. Just before that happends a battery indicator pops up and after that your Mac shuts down. I've waited another hour (to be sure) and reconnected the power cable. Then I've restarted my Mac and the lock screen with pass code was gone. I was able to get full access again. When I checked the find my iPhone page in iCloud my Mac was no longer locked and reported as lost.
I'm using a late 2016 Macbook Pro, 13 inch with touch bar, running MacOS 10.12.16
Draining the battery took me about 12 hours plus an extra hour waiting. Hopefully this helps you and other victims.
By the way, I don't use my iCloud email address for communicating. I only use it for my Apple ID.