Firstly, be open to your NOKs, telling people your mistakes beats having them find out the hard way. Besides, family will always support you and at least they can be on the lookout too.
Anyway the UML stunt all standard one, show you video of house kena splash paint, kena burn... Leave you voice messages threatening you, kill your family etc. Say will visit your workplace etc. At most they send runner to video your front door and scare you, say will lock you in and burn you.
Please lah, these dumb scammers are in Malaysia, all with their thrash talk.
Just block them, don't communicate with them, change phone number if possible.
They can't reach you, they can't disturb you.
Install CCTV and if you managed to video the runner, submit video to your IO.
Sleep well, eat well.