Caller: He said it was Maxwell from NBN

It came up as private on my Telstra landline so when he said the internet was running slowly and they were upgrading in my area I said it didn't bother me. He insisted that if I didn't upgrade I wouldn't have internet for 4 or 5 days and that someone would have to come to my house to disconnect it. I asked for a number to ring and check that it was genuine so he have me the number above. I said thank you very much and hung up.