Neighbour noise is horrible, been there. The realistic ladder: 1) keep a noise log (dates, times, type of noise) and record audio/video with timestamps, 2) approach them once more calmly in writing, 3) go to the town council and HDB, they can issue advisories, 4) mediation at the Community Mediation Centre (free, voluntary but often effective), 5) as a newer route there's the Community Disputes Resolution framework and a dedicated Community Relations Unit that can step in for severe cases. Court (Community Disputes Resolution Tribunal) is the last resort and needs strong evidence, hence the log. Manage expectations, this is slow. Please check the current process with your town council and the official CDRT/CRU info, the enforcement setup has been changing recently.