I rang Telstra who confirm that is a legitimate 3rd party sales co. affiliated with Telstra.
Telstra can remove you from that call list.
They can block the ph no from calling your landline if you wish - it will change the dialling tone of your phone though

Caller: Telstra

I answered it was Telstra. They asked to give my DOB to confirm it was me. I said you called me and I don't feel comfortable giving any info out. He then texted me a code from Telstra and told me my address to prove it.
I stayed on the line for 30 mins as he was trying to find me a better deal. I was already on a pretty good deal but he managed to take $2 off my monthly bill and give an extra 30GB data on my phone.
It came up on my phone as Melbourne, Australia but it clearly wasn't as he was asking where I lived (Melbourne) and what the weather was like and had the obvious thick accent.
A long call but I came out a winner and now hopefully I don't get another call for another 24 months.

Scam

Received a couple of calls from number since blocked, really sad that people get pleasure making nuisance calls they should get a life!!!!!

Blocked as spam.

Ha Ha Ha

You've been palmed off to a reseller. Your "updated" plan won't have the same network access and coverage of a Telstra direct plan. I answered all of the verification questions incorrectly and they still progressed the call until I ended it.

I get calls from these guys every day, sometimes twice. I've blocked the number so don't hear it ring and they don't leave a message.

Same experience as everyone else.

The caller had my details, He wanted me to confirm the call is recorded for coaching purposes, before letting the recording proceed I said the purpose of his call was not specific enough for us to proceed- "to ensure you have the best values in Telstra services", which is obviously subjective. I asked for clarifications for what that means- as shouldn't have to allow recording based on an ambiguous call, the guy went raising his voice and repeated his script over and over again.

Sorry don't have time for it and TELSTRA you need to ensure your contractor - whether it is TSA or not, doesn't not cause nuisance to your valued clients!

They ring at all sorts of hours but when I ring them back they claim office hours are 9 to 5 so why ring at 11:30pm???

Caller: tsa

telstra contract call centre asking if i was happy with my current deal Had one from Melb at 13:30 hrs, then Brisbane at 17:20 hrs, same thing. Called Telstra direct and they took me off their call centre list....hope it works!

A little concerned that they knew my last bill amount and names etc...

These infuriating pests will not stop phoning - every single day - even though I've blocked the number and so never answer. I wish I had their personal phone numbers ...

They won't give up! I blocked the number ages ago but can see that they keep calling, undaunted by the fact that no one ever answers. It's like some sort of dystopian nightmare these days.

Have been calling me daily for the past week between 2 and 3pm and then hanging up on without speaking. Have now blocked the number. I am with Telstra so if they are really working for them, then it has backfired on Telstra.

Same experience as others - I’ve lodged a complaint with ACMA DNC register.

Another call from this number has disturbed me. No message was left so they didn't actually want to speak to me, and so I've blocked the number.

Add another to the list that is registered with the DNC registry.

Many comments say this number is TSA Telco Group. I looked them up and they have a free-call number - 1800 994 608. Presumably they have to pay for all the calls made to this number. I rang and it was eventually answered. I didn't leave a message.

They just called me and I answered and then they said “hello!” In a young friendly voice and then hung up on me...