as of my knowledge, POLO verifies the employment documents (i.e, contracts, etc) and OWWA protects the OFW. POEA is the only one who can verify and has access to companies profile, if the company has no records or blacklisted. if it is in blacklisted, there is no way you can leave the country to work with that company.

btw, what do you mean by your "contract" is blacklisted?