Getting a lot of these calls from 8000 numbers, I live in a regional area, so never answer numbers II don't recognize, but these 8000 calls are coming in thick and fast now...

Someone called me from this number when I was busy with another call, but one minute later when I dialed this number three times to check, there was not even a ringing sound and no one answered.

Caller: Somebody saying they were from Amazon Prime

They said that somebody had used my account to purchase an iPhone and did I want to cancel it. I check my Amazon Account to see this was not true, Asked him who he was and he hung up.
Tried calling back but number was unavailable

Caller: Scammer claiming to be from the NBN.

Rang claiming to be from the NBN and that he was ringing to inform me that there were errors detected coming from my system and wanted to help me fix things. He started by asking me if I knew what my download speed was. When I replied why do I need to know that now I'm having no problems. I don't know what this is but it sounds like a scam. Before I finished my sentence he had hung up.