Caller: Call centre spoof number

First they called from 0406 933 232 I didn’t answer and just blocked.That was at 11.51 am, then they rang on this other spoofed number at 6.38pm.Which I also didn’t answer and have blocked.I know they will keep trying but I have picked the times they call.Which is generally around or just before or after meal times.You can’t stop this until the telecommunication companies servers use encryption for legitimate paid for numbers and not ones that are on there servers data banks that currently don’t have a paying customer.If they did that then we would always know a scammers call because of the exstra amount of digits of the incoming call