Caller: Tec Dept Telstra so she said

Received a call from the Technical Department of Telstra or so she said. Kept telling me that my computer or laptop was causing trouble. She wanted me to do something with my computer which I refused to do and said I was going to hang up now and ring Telstra in my town as they are really good. She rang me back and was quite cross that I had hung up on her. I told her again I was going to hang up and check with our local Telstra Office but she tried to get me to stay on the phone. I am sick of these people calling and we cannot block them as they use a different number each time.