Caller: Claimed to be Telstra Technical Helpdesk

I received a call from this number claiming to be a Telstra technical helpdesk. They sought access to my phone by asking me to download an app called Team Viewer onto my phone which is used to grant remote access. When I asked that they confirm their identity by providing alternate contact or response options (something every major entity has) they became defensive and gave me a fake name and employee ID number. They were unable to provide any details about me as a customer. PLEASE DO NOT TALK TO THESE PEOPLE!!!!!!!!