They've called us 3 times, but they never leave a message.

rang but i did not answer as my phone said spam

Caller took about 20 seconds to acknowledge that I'd picked up, sounds of a call centre in the background. Caller had a thick indian accent and advised that they were calling about my internet. When prompted as to who they're calling from, he said Telstra. I advised that I'm not a Telstra customer to which we said Telstra look after the IP addresses for Australia and there was a problem with my IP address. I pressed him on a few more IT related questions, but just hung up when it was clear that he was a scammer.