My elderly parents have been getting harassed by an 021 number over the last week, with several calls today. One of the phone calls swore at them down the line. Another made other one word comments. Others are just silent calls  I contacted Vodafone and txted 300, and it says that the number is not on their network. They say that they would need to have a record of at least 4 calls for it to be reported for abuse, which they have had.  According to netsafe, telcos can terminate callers from their network who are abusing it but I would need to find out what network they are on first 

Is there a way to find out what actual network it is on. I though 300 would do this, but all it does is say whether the number is on Vodafones network or not, if txting from a Vodafone account.