Claimed I had an Amazon Prime account and would be debited a monthly amount.

claimed my Amazon account is overdue for payment
I don't have a Amazon account

must be a scam

Scam. Automated message saying NBN now in my area and my internet connection will be disconnected

Scammer pretending to be Nicole from Australian Broadband Network threatening to disconnect internet. Get a real job, scammer.

Caller: Claimed to be Telstra

Claimed to be from Telstra investigations of internet usage.

Caller: an Indian accented man from the Telstra Internet Department

a man claiming to be from Telstra telling me of problems with my Internet connection and he wants to help me fix them.
Only problem I don't have anything to do with Telstra or problems with the Internet.
He couldn't tell me my name my address or any relevant information.