I just received a phone call from someone who asked if I was available to answer a few short questions about my household. 'No, not at all thank you' was my reply. To which the caller replied,
'I will call you every day, I will call you every day, I will call you every day' then hung up.
A search around the web shows a lot of folk getting abusive calls from these people (who apparently are in Manilla) so it might be worth putting their number in your phonebook so you can reply however you feel is appropriate if they call you.
The number is 01832448484