Pleasehelpme

I spoke to the boss of the ID, he claimed that what his tiler did was acceptable and therefore not deemed as a defect. And he won't be re-laying for me. He says that whatever was done is within the HDB guidelines... I asked some of the tilers which are doing my neighbours' units to go over to my unit and have a look, all of them say it is unacceptable.. I need a neutral party or an authority/expert to assess and get them to redo the work.. Call Radac but my ID is not under them... Any help here is appreciated! Thanks!

Hi all, I just collected key for my 4 room BTO in Sengkang and didn't opt for HDB flooring. So by default they only laid the tiles for kitchen and both toilets. I engaged an ID and they lay the tiles for me. They lay the tiles based on the kitchen tiles' height and as they progress, the height dropped.... When the tiles reached my toilets, there's a distinctive 1cm height difference between the toilet tiles and the tiles they laid... I assumed that it should be flushed to the same height....... See the pictures for reference. I asked the Building Service Centre person if there's a different in height of my kitchen and both toilets, the person brought a laser leveling device to assure me it's of the same height. So i concluded it's my ID's tiler's problem. But my ID's tiler told me that it is very very normal for the height of the passageway to be different with the toilet tiles. And told me that they will put a "curb/slope" to match the height.. But the point is from 1 end of the living room to my bedroom, there's a sink of 1.5cm... which they told me it's normal... I need to check with you guys if it really is normal... They told me it is totally impossible to make it same height... Is that true????? Please help me out on this and advise me!! Thanks!! Also, because of the "slanted" flooring, the gap between my doors are screwed up too..... Sorry for the long post