Caller: Telstra Telemarketer

1st call, saying our account was about to expire ... (I've never had any form of Telstra Service before, so saying I have an account, yet they need me to confirm my full name, contact number and email address for verification purposes = very suss) - 1st call placed in the morning

2nd call, saying they notice illegal activity from our Telstra account (the 2nd call was same day in the afternoon !!!)

Both times I asked for their name, number and manager's name.
At this point they say they are unable to provide their name and manager's name, and I hang up

Next time will just tell them to f*ck off.