1st Expert Tech Service Natalie Black Charged me $149.00 to replace Microsoft Security Essentials which I already had Internet

Someone called me on my phone, while I was on my computer, he said my computer was calling Microsoft reporting  errors, and that he worked for Microsoft. He was calling to fix the problem before my system crashed and to hurry and let him remote control my computer so he could fix it,  then he wanted  $149.00 to fix it.  I think he was Indian because his English was so bad, I  had to ask him many times to repeat to figure out what he was saying.

He told me I had 3100+ errors on my computer (don't know how he got in there to look at them) and it was because I didn't have a licensed copy of Microsoft Essentials Security.  I let him (supposedly) fix my computer, but he put the same Microsoft Essential Security on there and used a Defraggler to clean it up for 2 hours (which I could have done myself).  Can't see that he did anything for the $149 he charged.  I tried to call the phone number they gave me to cancel this event and it said the mailbox was full.  Unfortunately I put my charge on a debit card.  

Then I emailed them within the 48-72 hrs to cancel this offer on 12/18/2012.  Today 1/11/2013, I sent another email to director@experttechservice.com reminding them I have never received a reply and that I thought this was a fradulent occurence.  An error message came back that the  recipient cannot be reached.  So they probably pulled their email address.  If you need the email I sent them, I would be happy to send it to you.