Called both Ah Lek and Mr Wong, both did not solve my problem. I called Ah Lek his attitude is kinda crap, talking to him on the phone feels as if I owed him something, he did not come to my place because he said it's too far. For Mr Wong the contact number actually belongs to Ms Lee, they provided a backup plumber that not only feels like scam, but also did not solve my problem at all. In the end I found a trustworthy plumber at Kaodim called C and C One Construction. This is his contact number: Mr Chee +6017-365 5060. Unfortunately Kaodim is closing their platform soon, quite sad to see it go.

Taking back what I said about Mr Chee. My problem wasn't solved when I called him the 2nd time and he refused to solve it. I explained the problem to him and he refused to do inspection on the tank on top of my house. Only came to collect transportation fees and left. The first impression that he and his partner gave me was to make themselves look very professional, all of it was a lie since they don't seem to be capable of solving serious plumbing issues especially when water pump is involved.