Indian lady called me from this mobile said she was from Optus, explaining that my mobile data had run out. I currently work for Telstra/have a Telstra staff plan and she was calling from a mobile so I was suspicious.

I explained this and asked, so your from Optus then? She told me no actually I'm from Vodafone. At this point I asked for her employee ID number, to which she replied... '1234gof*ckyourself.com' and hung up. I immediately called back, she answered hello, I just said 'I'm reporting you' and hung up.