Hi, he's just showing off his very limited capabilities to you. Never
overestimate their capabilities

. Maybe he had to pay to get those data.
Their M.O is the same, to wreck havoc on your emotions by putting in fear but little to nothing they do will ever materialise to physically harm you.
If they send runners to bang at your door, so be it, your course of action is to immediately call 999. Splash paint, call 999. Harass in any other way or form, report or call 999. You get the idea?
They must be made to understand, this is Singapore, land of thousands of CCTV. Offenders caught will get mandatory caning. And they are no Macau triad gangsters. No harm will come to you or your family.
They harder they try, it only means they are losing you as a victim. Because they operate from overseas, they cannot come up with new ways, been like this since few years ago from my own experience
.
Keep ghosting, they will try all the usual tricks up their sleeves and WILL give up soon enough.