Do not answer these scum bags. Theys start off as if they are from Telstra offering 50% discount on your services for 6 months. All sound legit as they ask to verify who you are by sending a verification code to your mobile, exactly what Telstra do. The red flag was clear when they offered $1000.00 credit asking for Bank Account details to pay. This is when I challenged her and said this is a scam, she got annoyed and hung up.

Said they were Telstra and sent a code asking me to verify my account
Couldn’t answer my questions when asked where she was - clearly Indian scam centre