Need To Change Sewage Piping (big One)

[Chongchong 0]

Hi, there.

My mother in law's flat is at Ang Mo Kio older estate. About 30 years old.

Recently we notice that the sewage piping(near the ceiling) in her kitchen, is turning into black colour(like a black ring). It looks dirty and we were afraid of leaking. So we called HDB in to advise us what was wrong with that area. HDB came and Town council too. Town council said they charged $300 to change the pipe in 2 hours. I asked for their ID for Town Council and the man got angry and said that he didn't like people asked him this question. It's pissed me off too.

May I know, if anyone, got a good Plumber contact to share so that we can engage one our own. After changing the piping, we need to paint the ceiling etc too.

Thanks for your help.