Tried to call back but call instantly disconnects

This number ‭0488 862 265‬ called claiming to be Telstra but didn’t advise of the call being recorded or read any outbound calling declaration! Did not perform any ID with me either and by law as a customer you are required to provide 3 point of information to acce any sensitive information.. also they called in regards to a phone upgrade asking if I still wanted to do it even though I did this 2 months ago.

Answered and claimed to be Telstra but got my name wrong.
Was an Aussie speaking guy so not too sure what is going on.

Answered the phone but no one spoke then it hung up.

I called back but it went to busy signal.

Called, and couldn't contact back. Tried a few times.

I called back the number 0488 862 265 but the call didn't go through