Australia Reverse Phone Lookup

Telstra support called saying there's malware in my internet. I needed to go to my computer and he could help me clear with step by step instructions.
At this point I said I was busy and asked his name ( Asian sounding accent called Shaun Martin) and phone number and I would call back later as I was in a meeting.
I had previously argued that my computer was clean, to be told the malware was not on my computer but in the internet. I suggested he contact my internet supplier but he insisted I need to go to my computer

Saying a call from Telstra, it was regarding people hacking into my Telstra account and using my IP address. To confirm asked to call this number and gave a confirmation number.

Continuous calls lying about a hack and trying to get me to make changes to my configs