Rings multiple times a day and just hangs up. Seems related to similar 0488 815 numbers, as I have received calls from several variations all starting with 0488 815 ...

Same caller from 0488 815 xxx. I block every call with this prefix now. They just keep calling with different variations.

These people ring from different variations of 0488 815 .... I called back 0488 812 300 and landed in a call centre of some Superannuation Team company.