Ethical Hacker - Disk Decryptor - Locked out of Computer

Locked out of my personal computer via bicklocker from a job I quit. I can't access my personal c: because the login was linked to their domain and I unknowingly logged out of my business MS356 into my personal MS365 without realizing my laptop login was still linked to their domain, so when they locked my access it locked me out of my personal laptop. I don't want to pay 2k for the software that I will only use once.