Tried to ring back, number not connected.

Caller claims to be from Telstra claiming to be updating Modems in my area. After his five minute spiel asks me to open the AnyDesk web site, then tells me to click on "download now".
When I tell him "I am not allowed to click on buttons without initial research" he changes his tone, telling me that if don't click on the download button my internet will be disconnected within thirty seconds.
After further refusals to click, I then told him "he was wasting his time" he then called me what sounded like a dhobi-wallah and hung up, without giving me the chance to thank him for his time.