Quick Defender was marked as a scam by Microsoft and will not work since their objective is to get you to pay for it and run away.
http://answers.microsoft.com/en-us/windows/forum/window...
Your best bet since mor ethan likely your not going to be able to get your money back is to contact
www.IC3.Gov and submit a complaint to the FBI cyber criminal center.
Just explain what happened and they will work with you to get your money back.