Just got a DELIGHTFUL call from some marble mouthed dimwit who was calling from "Microsoft" about my "Microsoft Computer."  I answered the phone thinking it was someone calling me regarding something completely unrelated.
Anyway, I answered the phone and it sounded like the Dude was in La-La land then had that "Oh, I have a CALLER!! Yeah!".  He did NOT know his script and stumbled through two words, paused,and when I asked him who he was he gave his name really quickly and then said "I'm calling from Microsoft regarding your Microsoft Computer."  that is when I hung up.  My Computer does not have a Virus, plus it doesn't like it when other computers try to repair it
When I  got a call from a similar company years ago I was "Oh,I don't have my Credit card.  My dog ate it. So I cancelled the card." they hung up.