dont trust this number

A warning came up on the screen to say I had been infected by a virus, tried to exit screen but it was locked, couldn't do anything. Screen looked lagit, so rang the 1800 no. They wanted to take control of computer to get rid of virus, I said no I would run virus checker.

This is a scam saying they will fix virus infection and want $49.99 when I queried if they were genuine they shut every thing down on my computer