Microsoft 365 Tenant Lockout - Malicious Actor

Question

Malicious contractor has locked out our business out of Microsoft 365 Global Admin and is taking actions to hurt our business via our 365 email accounts. Have tried to contact support multiple times including Data Protection team to no avail. In one case, Microsoft support simply called this malicious contractor at the number provided under the Global Admin account and he told them not to worry about it, so they closed the case.