I have received 7 calls from mobile numbers starting with 0488 813 and ending with a different set of last three digits each time. One of the numbers was this one 0488 813 786. I have not answered any of them as I do not recognise the numbers and they have not left a message each time. As others have noted they did not get through when calling these numbers back, I assume it is marketing or a scam.

every day there is another call from 0488 813 xxx - the last 3 digits are different each time: today 0488 813 678, yesterday 0488 813 468, the day before 0488 813 786
my phone silences unknown numbers so I just get a notification the number called - starting to become very annoying

Hung up when I answered. Blocked them