Can't get past the system lock PIN code I locked my MacBook using Find My iPhone and now when attempting to start using it again, I cannot type my PIN into the unlock section. Nothing happens. I can't even click on sleep, restart, shut down or the internet options.

I tried Command-Option-R and Command-Option-R-P. Both just came up with a different password screen which I put the PIN into and then they went back to the PIN screen. I have no idea what else I can do.
There are multiple options available.  


You can purchase a EFI Rom chip for your particular model computer, attach it to the logic board and it will bypass the system EFI.  http://www.cmizapper.com/components/chips.html
You can attempt to rewrite the existing EFI chip  https://ghostlyhaks.com/blog/blog/hacking/18-apple-efi-bypass
You can attempt to brute force the password with an Arduino Teensy https://github.com/orvtech/efi-bruteforce or similar. http://www.cmizapper.com/products/brutus.html