Australia Reverse Phone Lookup

Someone purporting to be from Telstra rang our home phone to discuss our computer.
My elderly Mum took the call. When she explained that she knew nothing about the computer and asked for a call back number this what she received.
We are on the no call list and are tired of these useless sales calls.

A call claiming to be from Telstra. Told me my computer was full of malware etc (which it well could be) and asked me sign up for a 1, 2 or 5 year deal to protect my computer. At no stage did they verify our Telstra account number or the account name, which immediately made me suspicious. I ended the call after they asked which bank we use because certain bank account holders would get a discount.