Just had that dodgy tech phone call for Windows, by those Indian guys. Just told them I don't use Windows and hung up. Never gave them a chance to say anything much
Despite their business being legit', the authorities should nail their hides to a wall and shut them down.
Personally, I'd stick them on a really slow boat back to India and make them eek out a living in the Bombay or Calcutta slums, where they belong. Gives everyone from there that's honest and upstanding a bad name. But like all rats, you give them an inch and they'll take a mile.