I was travel to Manila on 3 Jan 2016 and when returning home on 8th Jan 2016, the immigration officer stopped me. He was telling me I was blacklisted on 2012 and wondering how can I entered the country.
After some discussion and appeal by telling I have my girlfriend in Philippines then he blacklisted for another 2 years.

I would like to remove the blacklist but do not know the way or any legal firm that can help me to do.
Please advice or provide any legal firm that can help on it.

Hire an immigration attorney in that country to file an appeal with the immigration department.

The issue is why were you blacklisted in the first place? What did you do, to get on the blacklist in 2012.