Caller: Identified themselves as Telstra

They kept calling me insisting my mobile plan had expired and that I should complete a DocuSign document to allow an upgrade to a new plan.
When I viewed the document I realised they were from a so-called Telstra Partner called TWorld Group. I was concerned as they had old data on my document, the Telstra logo was in black and white not colour, and they wanted me to provide my drivers licence details.
I eventually told them I would deal direct with Telstra.
After much discussion Telstra did confirm they were a partner. They also confirmed that my mobile plans had not yet expired and changing plans would result in cancellation charges - which hadn't been mentioned by TWorld Group.
I have lodged a complaint with Telstra as the TWorld group company website (tworld.net.au) lists a mobile number only as it's main contact number, and it's business location as a kiosk in a shopping centre in Lidcombe NSW.
I am not happy dealing with such a small company, when my contract is with Telstra, and am even less happy that such a company has access to my actual account details.
The whole thing is pretty dodgy as far as I am concerned.

(02) 8004 3965 continually calling me and I don’t pick up. When I put my phone on no caller ID and call it back the message says it has been disconnected.
This is definitely a dodgy scammer.
I am sure of it

I rang back the number (02) 8004 3267 once but got disconnected

Caller said they were from Telsta and wanted to offer me a better plan than what I was on already.
The offer was good as it was a decrease in my current monthly bill. They quoted my details over the phone, physical and email address, d.o.b. mothers name, average bill etc.
They sent through a DocuSign document for me to sign and then repeatedly called back after only 5 minutes. I hadn't even had time to open my emails and read the document before they were calling.

Telstra representatives have called over the years doing bill reviews and offering me better deals & I'd never had to digitally sign another contract. This time I felt very uncomfortable with the tactic used by the caller so did not proceed.

Caller: Telstra Scam

They have name/phone database (potentially from Telstra as mentioned in another comment) so they know your first name. All other details are wrong/old - felt very scammy (free phone upgrade etc..).

I rang back the number (02) 8004 3267, spoke with someone who hung up right away