Received legitimate looking letter from Telstra requesting I call them to confirm some details. I rang and after many automatic phone transfers (I could hear different ring tones as my phone call bounced from one number to another) I was welcomed by an American accented lady. She legitimately new of my change of primary contact number, and asked valid questions, including that I verify my birthdate and home address. However she set of red flags when she asked me if we spoke other languages at home, (I avoided answering this) and the asked for my drivers license number. At that point I said that we'd covered the reason for this call and felt that I didn't want to waster any more of her time. Strange that Telstra would ask for so much irrelevant info.

I was receiving calls from 1800 870 456 number and did not answer them then they started to SMS me. Looked up the number and it was a scam. So blocked the number and now they are sending me letters which do look like they are from Telstra asking me to ring the above number to update the details on my account - even have my account number. So letter is going straight in the bin.